diff --git a/Plugins/SQLiteDriverPlugin/SQLitePlugin.swift b/Plugins/SQLiteDriverPlugin/SQLitePlugin.swift
index 2bc91570b..c30e91f18 100644
--- a/Plugins/SQLiteDriverPlugin/SQLitePlugin.swift
+++ b/Plugins/SQLiteDriverPlugin/SQLitePlugin.swift
@@ -440,6 +440,18 @@ final class SQLitePluginDriver: PluginDatabaseDriver, @unchecked Sendable {
     var supportsSchemas: Bool { false }
     var supportsTransactions: Bool { true }
 
+    var capabilities: PluginCapabilities {
+        [
+            .parameterizedQueries,
+            .transactions,
+            .alterTableDDL,
+            .foreignKeyToggle,
+            .truncateTable,
+            .cancelQuery,
+            .batchExecute,
+        ]
+    }
+
     func quoteIdentifier(_ name: String) -> String {
         let escaped = name.replacingOccurrences(of: "`", with: "``")
         return "`\(escaped)`"
diff --git a/Plugins/TableProPluginKit/PluginCapabilities.swift b/Plugins/TableProPluginKit/PluginCapabilities.swift
new file mode 100644
index 000000000..bb9d18d8a
--- /dev/null
+++ b/Plugins/TableProPluginKit/PluginCapabilities.swift
@@ -0,0 +1,22 @@
+import Foundation
+
+public struct PluginCapabilities: OptionSet, Sendable {
+    public let rawValue: UInt32
+
+    public init(rawValue: UInt32) {
+        self.rawValue = rawValue
+    }
+
+    public static let materializedViews     = PluginCapabilities(rawValue: 1 << 0)
+    public static let foreignTables         = PluginCapabilities(rawValue: 1 << 1)
+    public static let storedProcedures      = PluginCapabilities(rawValue: 1 << 2)
+    public static let userFunctions         = PluginCapabilities(rawValue: 1 << 3)
+    public static let alterTableDDL         = PluginCapabilities(rawValue: 1 << 4)
+    public static let foreignKeyToggle      = PluginCapabilities(rawValue: 1 << 5)
+    public static let truncateTable         = PluginCapabilities(rawValue: 1 << 6)
+    public static let multiSchema           = PluginCapabilities(rawValue: 1 << 7)
+    public static let parameterizedQueries  = PluginCapabilities(rawValue: 1 << 8)
+    public static let cancelQuery           = PluginCapabilities(rawValue: 1 << 9)
+    public static let batchExecute          = PluginCapabilities(rawValue: 1 << 10)
+    public static let transactions          = PluginCapabilities(rawValue: 1 << 11)
+}
diff --git a/Plugins/TableProPluginKit/PluginDatabaseDriver.swift b/Plugins/TableProPluginKit/PluginDatabaseDriver.swift
index 4fd8d3a3c..a4676d25a 100644
--- a/Plugins/TableProPluginKit/PluginDatabaseDriver.swift
+++ b/Plugins/TableProPluginKit/PluginDatabaseDriver.swift
@@ -31,6 +31,8 @@ public struct PluginRowChange: Sendable {
 }
 
 public protocol PluginDatabaseDriver: AnyObject, Sendable {
+    var capabilities: PluginCapabilities { get }
+
     // Connection
     func connect() async throws
     func disconnect()
@@ -141,6 +143,8 @@ public protocol PluginDatabaseDriver: AnyObject, Sendable {
 }
 
 public extension PluginDatabaseDriver {
+    var capabilities: PluginCapabilities { [] }
+
     var supportsSchemas: Bool { false }
 
     func fetchSchemas() async throws -> [String] { [] }
diff --git a/Plugins/TableProPluginKit/PluginProcedureFunctionSupport.swift b/Plugins/TableProPluginKit/PluginProcedureFunctionSupport.swift
new file mode 100644
index 000000000..3cc8807be
--- /dev/null
+++ b/Plugins/TableProPluginKit/PluginProcedureFunctionSupport.swift
@@ -0,0 +1,20 @@
+import Foundation
+
+public protocol PluginProcedureFunctionSupport {
+    func fetchProcedures(schema: String?) async throws -> [PluginRoutineInfo]
+    func fetchFunctions(schema: String?) async throws -> [PluginRoutineInfo]
+    func fetchProcedureDDL(name: String, schema: String?) async throws -> String
+    func fetchFunctionDDL(name: String, schema: String?) async throws -> String
+}
+
+public struct PluginRoutineInfo: Codable, Sendable {
+    public let name: String
+    public let returnType: String?
+    public let language: String?
+
+    public init(name: String, returnType: String? = nil, language: String? = nil) {
+        self.name = name
+        self.returnType = returnType
+        self.language = language
+    }
+}
diff --git a/TablePro/Core/Autocomplete/SQLContextAnalyzer.swift b/TablePro/Core/Autocomplete/SQLContextAnalyzer.swift
index d825656fa..8b1cdf3d3 100644
--- a/TablePro/Core/Autocomplete/SQLContextAnalyzer.swift
+++ b/TablePro/Core/Autocomplete/SQLContextAnalyzer.swift
@@ -6,6 +6,17 @@
 //
 
 import Foundation
+import os
+
+private let regexLogger = Logger(subsystem: "com.TablePro", category: "SQLContextAnalyzer.Regex")
+
+private func compileRegex(_ pattern: String, options: NSRegularExpression.Options = []) -> NSRegularExpression {
+    if let regex = try? NSRegularExpression(pattern: pattern, options: options) {
+        return regex
+    }
+    regexLogger.fault("Failed to compile static regex pattern: \(pattern, privacy: .public)")
+    return NSRegularExpression()
+}
 
 /// Type of SQL clause the cursor is in
 enum SQLClauseType {
@@ -188,80 +199,28 @@ final class SQLContextAnalyzer {
             // SELECT is most general
             ("\\bSELECT\\s+[^;]*$", .select),
         ]
-        return patterns.compactMap { pattern, clause in
-            guard let regex = try? NSRegularExpression(
-                pattern: pattern, options: .caseInsensitive
-            ) else {
-                assertionFailure("Invalid SQL clause regex pattern: \(pattern)")
-                return nil
-            }
-            return (regex, clause)
+        return patterns.map { pattern, clause in
+            (compileRegex(pattern, options: .caseInsensitive), clause)
         }
     }()
 
-    /// Pre-compiled regex for removing strings and comments
-    private static let singleQuoteStringRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(pattern: "'[^']*'") {
-            return regex
-        }
-        assertionFailure("Failed to compile singleQuoteStringRegex - invalid pattern")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let singleQuoteStringRegex = compileRegex("'[^']*'")
 
-    private static let doubleQuoteStringRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(pattern: "\"[^\"]*\"") {
-            return regex
-        }
-        assertionFailure("Failed to compile doubleQuoteStringRegex - invalid pattern")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let doubleQuoteStringRegex = compileRegex("\"[^\"]*\"")
 
-    private static let blockCommentRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(pattern: "/\\*[\\s\\S]*?\\*/") {
-            return regex
-        }
-        assertionFailure("Failed to compile blockCommentRegex - invalid pattern")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let blockCommentRegex = compileRegex("/\\*[\\s\\S]*?\\*/")
 
-    private static let lineCommentRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(pattern: "--[^\n]*") {
-            return regex
-        }
-        assertionFailure("Failed to compile lineCommentRegex - invalid pattern")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let lineCommentRegex = compileRegex("--[^\n]*")
 
-    /// Combined regex for removing strings and comments in a single pass (SVC-13)
-    private static let stringsAndCommentsRegex: NSRegularExpression = {
-        // Alternation: single-quoted strings | double-quoted strings | block comments | line comments
-        let pattern = #"'[^']*'|"[^"]*"|/\*[\s\S]*?\*/|--[^\n]*"#
-        if let regex = try? NSRegularExpression(pattern: pattern) {
-            return regex
-        }
-        assertionFailure("Failed to compile stringsAndCommentsRegex - invalid pattern")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let stringsAndCommentsRegex = compileRegex(
+        #"'[^']*'|"[^"]*"|/\*[\s\S]*?\*/|--[^\n]*"#
+    )
 
-    private static let cteFirstRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(
-            pattern: "(?i)\\bWITH\\s+(?:RECURSIVE\\s+)?([\\w]+)\\s+AS\\s*\\("
-        ) {
-            return regex
-        }
-        assertionFailure("Failed to compile cteFirstRegex")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let cteFirstRegex = compileRegex(
+        "(?i)\\bWITH\\s+(?:RECURSIVE\\s+)?([\\w]+)\\s+AS\\s*\\("
+    )
 
-    private static let cteCommaRegex: NSRegularExpression = {
-        if let regex = try? NSRegularExpression(
-            pattern: "(?i),\\s*([\\w]+)\\s+AS\\s*\\("
-        ) {
-            return regex
-        }
-        assertionFailure("Failed to compile cteCommaRegex")
-        return try! NSRegularExpression(pattern: "(?!)")
-    }()
+    private static let cteCommaRegex = compileRegex("(?i),\\s*([\\w]+)\\s+AS\\s*\\(")
 
     private static let tableRefRegexes: [NSRegularExpression] = {
         let patterns = [
@@ -274,7 +233,7 @@ final class SQLContextAnalyzer {
             "(?i)\\bINSERT\\s+INTO\\s+[`\"']?([\\w.]+)[`\"']?",
             "(?i)\\bCREATE\\s+(?:UNIQUE\\s+)?INDEX\\s+\\w+\\s+ON\\s+[`\"']?([\\w.]+)[`\"']?"
         ]
-        return patterns.compactMap { try? NSRegularExpression(pattern: $0) }
+        return patterns.map { compileRegex($0) }
     }()
 
     // MARK: - UTF-16 Helpers
diff --git a/TablePro/Core/Database/DatabaseManager+Sessions.swift b/TablePro/Core/Database/DatabaseManager+Sessions.swift
index 1a9ef4acd..23403c4ab 100644
--- a/TablePro/Core/Database/DatabaseManager+Sessions.swift
+++ b/TablePro/Core/Database/DatabaseManager+Sessions.swift
@@ -6,6 +6,7 @@
 //
 
 import AppKit
+import Combine
 import Foundation
 import os
 import TableProPluginKit
@@ -378,13 +379,17 @@ extension DatabaseManager {
     internal func setSession(_ session: ConnectionSession, for connectionId: UUID) {
         activeSessions[connectionId] = session
         connectionStatusVersions[connectionId, default: 0] &+= 1
-        NotificationCenter.default.post(name: .connectionStatusDidChange, object: connectionId)
+        AppEvents.shared.connectionStatusChanged.send(
+            ConnectionStatusChange(connectionId: connectionId, status: session.status)
+        )
     }
 
     internal func removeSessionEntry(for connectionId: UUID) {
         activeSessions.removeValue(forKey: connectionId)
         connectionStatusVersions.removeValue(forKey: connectionId)
-        NotificationCenter.default.post(name: .connectionStatusDidChange, object: connectionId)
+        AppEvents.shared.connectionStatusChanged.send(
+            ConnectionStatusChange(connectionId: connectionId, status: .disconnected)
+        )
     }
 
     #if DEBUG
diff --git a/TablePro/Core/Events/AppEvents.swift b/TablePro/Core/Events/AppEvents.swift
new file mode 100644
index 000000000..d451aca23
--- /dev/null
+++ b/TablePro/Core/Events/AppEvents.swift
@@ -0,0 +1,23 @@
+//
+//  AppEvents.swift
+//  TablePro
+//
+
+import Combine
+import Foundation
+
+@MainActor
+final class AppEvents {
+    static let shared = AppEvents()
+
+    let themeChanged = PassthroughSubject<Void, Never>()
+
+    let connectionStatusChanged = PassthroughSubject<ConnectionStatusChange, Never>()
+
+    private init() {}
+}
+
+struct ConnectionStatusChange: Sendable {
+    let connectionId: UUID
+    let status: ConnectionStatus
+}
diff --git a/TablePro/Core/Services/AppServices.swift b/TablePro/Core/Services/AppServices.swift
new file mode 100644
index 000000000..1007ddd1b
--- /dev/null
+++ b/TablePro/Core/Services/AppServices.swift
@@ -0,0 +1,46 @@
+//
+//  AppServices.swift
+//  TablePro
+//
+
+import SwiftUI
+
+@MainActor
+struct AppServices {
+    let appEvents: AppEvents
+    let appSettings: AppSettingsManager
+    let connectionStorage: ConnectionStorage
+    let databaseManager: DatabaseManager
+    let pluginManager: PluginManager
+    let schemaService: SchemaService
+    let queryHistoryStorage: QueryHistoryStorage
+    let sqlFavoriteManager: SQLFavoriteManager
+    let aiChatStorage: AIChatStorage
+    let syncTracker: SyncChangeTracker
+    let themeEngine: ThemeEngine
+
+    static let live = AppServices(
+        appEvents: .shared,
+        appSettings: .shared,
+        connectionStorage: .shared,
+        databaseManager: .shared,
+        pluginManager: .shared,
+        schemaService: .shared,
+        queryHistoryStorage: .shared,
+        sqlFavoriteManager: .shared,
+        aiChatStorage: .shared,
+        syncTracker: .shared,
+        themeEngine: .shared
+    )
+}
+
+private struct AppServicesEnvironmentKey: EnvironmentKey {
+    @MainActor static var defaultValue: AppServices { .live }
+}
+
+extension EnvironmentValues {
+    var appServices: AppServices {
+        get { self[AppServicesEnvironmentKey.self] }
+        set { self[AppServicesEnvironmentKey.self] = newValue }
+    }
+}
diff --git a/TablePro/Core/Services/Infrastructure/AppNotifications.swift b/TablePro/Core/Services/Infrastructure/AppNotifications.swift
index 13937ba50..510054529 100644
--- a/TablePro/Core/Services/Infrastructure/AppNotifications.swift
+++ b/TablePro/Core/Services/Infrastructure/AppNotifications.swift
@@ -17,7 +17,6 @@ extension Notification.Name {
     // MARK: - Connections
 
     static let connectionUpdated = Notification.Name("connectionUpdated")
-    static let connectionStatusDidChange = Notification.Name("connectionStatusDidChange")
     static let databaseDidConnect = Notification.Name("databaseDidConnect")
     static let exportConnections = Notification.Name("exportConnections")
     static let importConnections = Notification.Name("importConnections")
diff --git a/TablePro/Core/Services/Infrastructure/MainSplitViewController.swift b/TablePro/Core/Services/Infrastructure/MainSplitViewController.swift
index f2e0704a2..4e382f2ee 100644
--- a/TablePro/Core/Services/Infrastructure/MainSplitViewController.swift
+++ b/TablePro/Core/Services/Infrastructure/MainSplitViewController.swift
@@ -9,6 +9,7 @@
 //
 
 import AppKit
+import Combine
 import os
 import SwiftUI
 
@@ -45,7 +46,7 @@ internal final class MainSplitViewController: NSSplitViewController, InspectorVi
 
     // MARK: - Observers
 
-    private var connectionStatusObserver: NSObjectProtocol?
+    private var connectionStatusCancellable: AnyCancellable?
 
     // MARK: - Init
 
@@ -196,24 +197,17 @@ internal final class MainSplitViewController: NSSplitViewController, InspectorVi
     // MARK: - Observers
 
     private func installObservers() {
-        guard connectionStatusObserver == nil else { return }
-        connectionStatusObserver = NotificationCenter.default.addObserver(
-            forName: .connectionStatusDidChange,
-            object: nil,
-            queue: .main
-        ) { [weak self] _ in
-            MainActor.assumeIsolated {
+        guard connectionStatusCancellable == nil else { return }
+        connectionStatusCancellable = AppEvents.shared.connectionStatusChanged
+            .receive(on: RunLoop.main)
+            .sink { [weak self] _ in
                 self?.handleConnectionStatusChange()
             }
-        }
         handleConnectionStatusChange()
     }
 
     private func removeObservers() {
-        if let observer = connectionStatusObserver {
-            NotificationCenter.default.removeObserver(observer)
-            connectionStatusObserver = nil
-        }
+        connectionStatusCancellable = nil
     }
 
     // MARK: - Toolbar
diff --git a/TablePro/Core/Services/Infrastructure/SettingsNotifications.swift b/TablePro/Core/Services/Infrastructure/SettingsNotifications.swift
index ae67f08b9..f3e0d98b3 100644
--- a/TablePro/Core/Services/Infrastructure/SettingsNotifications.swift
+++ b/TablePro/Core/Services/Infrastructure/SettingsNotifications.swift
@@ -21,10 +21,6 @@ extension Notification.Name {
     /// Observers should reload fonts via ThemeEngine.shared.reloadFontCaches().
     static let accessibilityTextSizeDidChange = Notification.Name("accessibilityTextSizeDidChange")
 
-    /// Posted when the active theme changes (colors, fonts, or entire theme switch).
-    /// Used by AppKit components that cannot observe @Observable directly.
-    static let themeDidChange = Notification.Name("themeDidChange")
-
     /// Posted when terminal settings change (font, theme, cursor, etc.)
     /// Used by terminal views to live-update configuration.
     static let terminalSettingsDidChange = Notification.Name("terminalSettingsDidChange")
diff --git a/TablePro/Core/Storage/SSHProfileStorage.swift b/TablePro/Core/Storage/SSHProfileStorage.swift
index a1a3baa5c..f438ebcdd 100644
--- a/TablePro/Core/Storage/SSHProfileStorage.swift
+++ b/TablePro/Core/Storage/SSHProfileStorage.swift
@@ -78,11 +78,11 @@ final class SSHProfileStorage {
     }
 
     func deleteProfile(_ profile: SSHProfile) {
-        SyncChangeTracker.shared.markDeleted(.sshProfile, id: profile.id.uuidString)
         var profiles = loadProfiles()
         guard !lastLoadFailed else { return }
         profiles.removeAll { $0.id == profile.id }
         saveProfiles(profiles)
+        SyncChangeTracker.shared.markDeleted(.sshProfile, id: profile.id.uuidString)
 
         deleteSSHPassword(for: profile.id)
         deleteKeyPassphrase(for: profile.id)
diff --git a/TablePro/Core/Storage/TagStorage.swift b/TablePro/Core/Storage/TagStorage.swift
index b461fa11a..a19003069 100644
--- a/TablePro/Core/Storage/TagStorage.swift
+++ b/TablePro/Core/Storage/TagStorage.swift
@@ -77,10 +77,10 @@ final class TagStorage {
     /// Delete a custom tag (presets cannot be deleted)
     func deleteTag(_ tag: ConnectionTag) {
         guard !tag.isPreset else { return }
-        SyncChangeTracker.shared.markDeleted(.tag, id: tag.id.uuidString)
         var tags = loadTags()
         tags.removeAll { $0.id == tag.id }
         saveTags(tags)
+        SyncChangeTracker.shared.markDeleted(.tag, id: tag.id.uuidString)
     }
 
     /// Get tag by ID
diff --git a/TablePro/Core/Utilities/Connection/EnvVarResolver.swift b/TablePro/Core/Utilities/Connection/EnvVarResolver.swift
index 3378ed193..00a43826b 100644
--- a/TablePro/Core/Utilities/Connection/EnvVarResolver.swift
+++ b/TablePro/Core/Utilities/Connection/EnvVarResolver.swift
@@ -11,11 +11,14 @@ import os
 internal enum EnvVarResolver {
     private static let logger = Logger(subsystem: "com.TablePro", category: "EnvVarResolver")
 
-    // Matches ${VAR_NAME} or $VAR_NAME
-    // swiftlint:disable:next force_try
-    private static let pattern = try! NSRegularExpression(
-        pattern: #"\$\{([A-Za-z_][A-Za-z0-9_]*)\}|\$([A-Za-z_][A-Za-z0-9_]*)"#
-    )
+    private static let pattern: NSRegularExpression = {
+        let source = #"\$\{([A-Za-z_][A-Za-z0-9_]*)\}|\$([A-Za-z_][A-Za-z0-9_]*)"#
+        if let regex = try? NSRegularExpression(pattern: source) {
+            return regex
+        }
+        logger.fault("Failed to compile EnvVarResolver pattern: \(source, privacy: .public)")
+        return NSRegularExpression()
+    }()
 
     /// Resolve environment variable references in a string.
     /// Unresolved variables are left as-is and logged as warnings.
diff --git a/TablePro/Models/Query/QueryResult.swift b/TablePro/Models/Query/QueryResult.swift
index 92434a0fc..7a71aea86 100644
--- a/TablePro/Models/Query/QueryResult.swift
+++ b/TablePro/Models/Query/QueryResult.swift
@@ -169,7 +169,7 @@ struct ForeignKeyInfo: Identifiable, Hashable {
 }
 
 /// Connection status
-enum ConnectionStatus: Equatable {
+enum ConnectionStatus: Equatable, Sendable {
     case disconnected
     case connecting
     case connected
diff --git a/TablePro/TableProApp.swift b/TablePro/TableProApp.swift
index 6e08c8730..e2366ab1a 100644
--- a/TablePro/TableProApp.swift
+++ b/TablePro/TableProApp.swift
@@ -644,6 +644,7 @@ struct TableProApp: App {
                     hideMiniaturizeButton: true,
                     hideZoomButton: true
                 ))
+                .environment(\.appServices, .live)
         }
         .windowResizability(.contentSize)
         .windowStyle(.hiddenTitleBar)
@@ -652,6 +653,7 @@ struct TableProApp: App {
         WindowGroup("New Connection", id: SceneId.connectionForm, for: UUID?.self) { $editingId in
             ConnectionFormView(connectionId: editingId ?? nil)
                 .background(WindowChromeConfigurator(restorable: false))
+                .environment(\.appServices, .live)
         }
         .windowResizability(.contentMinSize)
         .defaultSize(width: 820, height: 600)
@@ -659,6 +661,7 @@ struct TableProApp: App {
 
         Window("Integrations Activity", id: SceneId.integrationsActivity) {
             IntegrationsActivityView()
+                .environment(\.appServices, .live)
         }
         .windowResizability(.contentMinSize)
         .defaultSize(width: 960, height: 600)
@@ -673,6 +676,7 @@ struct TableProApp: App {
         Settings {
             SettingsView()
                 .environment(updaterBridge)
+                .environment(\.appServices, .live)
         }
     }
 }
diff --git a/TablePro/Theme/ThemeEngine.swift b/TablePro/Theme/ThemeEngine.swift
index d9b03ea49..2add9bf55 100644
--- a/TablePro/Theme/ThemeEngine.swift
+++ b/TablePro/Theme/ThemeEngine.swift
@@ -8,6 +8,7 @@
 
 import AppKit
 import CodeEditSourceEditor
+import Combine
 import Foundation
 import Observation
 import os
@@ -371,7 +372,7 @@ internal final class ThemeEngine {
     // MARK: - Notifications
 
     private func notifyThemeDidChange() {
-        NotificationCenter.default.post(name: .themeDidChange, object: self)
+        AppEvents.shared.themeChanged.send(())
     }
 
     // MARK: - Accessibility
diff --git a/TablePro/ViewModels/QuickSwitcherViewModel.swift b/TablePro/ViewModels/QuickSwitcherViewModel.swift
index 2714d954f..dd6784d6c 100644
--- a/TablePro/ViewModels/QuickSwitcherViewModel.swift
+++ b/TablePro/ViewModels/QuickSwitcherViewModel.swift
@@ -14,6 +14,8 @@ import os
 internal final class QuickSwitcherViewModel {
     private static let logger = Logger(subsystem: "com.TablePro", category: "QuickSwitcherViewModel")
 
+    @ObservationIgnored private let services: AppServices
+
     // MARK: - State
 
     var searchText = "" {
@@ -33,6 +35,10 @@ internal final class QuickSwitcherViewModel {
     /// Maximum number of results to display
     private let maxResults = 100
 
+    init(services: AppServices = .live) {
+        self.services = services
+    }
+
     // MARK: - Loading
 
     /// Load all searchable items from the database schema, databases, schemas, and history
@@ -71,7 +77,7 @@ internal final class QuickSwitcherViewModel {
         }
 
         // Databases
-        if let driver = DatabaseManager.shared.driver(for: connectionId) {
+        if let driver = services.databaseManager.driver(for: connectionId) {
             do {
                 let databases = try await driver.fetchDatabases()
                 for db in databases {
@@ -86,7 +92,7 @@ internal final class QuickSwitcherViewModel {
                 Self.logger.warning("Failed to fetch databases for quick switcher: \(error.localizedDescription, privacy: .public)")
             }
 
-            if PluginManager.shared.supportsSchemaSwitching(for: databaseType) {
+            if services.pluginManager.supportsSchemaSwitching(for: databaseType) {
                 do {
                     let schemas = try await driver.fetchSchemas()
                     for schema in schemas {
@@ -104,7 +110,7 @@ internal final class QuickSwitcherViewModel {
         }
 
         // Recent query history (last 50)
-        let historyEntries = await QueryHistoryStorage.shared.fetchHistory(
+        let historyEntries = await services.queryHistoryStorage.fetchHistory(
             limit: 50,
             connectionId: connectionId
         )
diff --git a/TablePro/Views/AIChat/AIChatContextChipView.swift b/TablePro/Views/AIChat/AIChatContextChipView.swift
index 9c76d6079..7314a3410 100644
--- a/TablePro/Views/AIChat/AIChatContextChipView.swift
+++ b/TablePro/Views/AIChat/AIChatContextChipView.swift
@@ -21,7 +21,7 @@ struct AIChatContextChipView: View {
             if let onRemove {
                 Button(action: onRemove) {
                     Image(systemName: "xmark")
-                        .font(.system(size: 9, weight: .semibold))
+                        .font(.caption2.weight(.semibold))
                 }
                 .buttonStyle(.plain)
                 .foregroundStyle(.secondary)
diff --git a/TablePro/Views/AIChat/ChatComposerView.swift b/TablePro/Views/AIChat/ChatComposerView.swift
index f06568f57..ddc6795c5 100644
--- a/TablePro/Views/AIChat/ChatComposerView.swift
+++ b/TablePro/Views/AIChat/ChatComposerView.swift
@@ -58,9 +58,11 @@ struct ChatComposerView: View {
                 if isFocused {
                     IntelligenceFocusBorder(shape: shape)
                         .transition(.opacity)
+                        .accessibilityHidden(true)
                 } else {
                     shape.stroke(Color(nsColor: .separatorColor), lineWidth: 0.5)
                         .transition(.opacity)
+                        .accessibilityHidden(true)
                 }
             }
             .animation(.easeOut(duration: 0.25), value: isFocused)
diff --git a/TablePro/Views/ConnectionForm/Toolbar/TestConnectionStatusButton.swift b/TablePro/Views/ConnectionForm/Toolbar/TestConnectionStatusButton.swift
index 876ea49ba..febaa0d8e 100644
--- a/TablePro/Views/ConnectionForm/Toolbar/TestConnectionStatusButton.swift
+++ b/TablePro/Views/ConnectionForm/Toolbar/TestConnectionStatusButton.swift
@@ -22,6 +22,18 @@ struct TestConnectionStatusButton: View {
         .disabled(coordinator.isTesting
                   || coordinator.isInstallingPlugin
                   || !coordinator.isFormValid)
+        .help(helpText)
+        .accessibilityLabel(helpText)
+    }
+
+    private var helpText: String {
+        if coordinator.isTesting {
+            return String(localized: "Testing connection")
+        }
+        if coordinator.testSucceeded {
+            return String(localized: "Connection succeeded")
+        }
+        return String(localized: "Test the current connection settings")
     }
 
     @ViewBuilder
diff --git a/TablePro/Views/ERDiagram/ERDiagramNodeRenderer.swift b/TablePro/Views/ERDiagram/ERDiagramNodeRenderer.swift
index cc51db8f4..04fd701e0 100644
--- a/TablePro/Views/ERDiagram/ERDiagramNodeRenderer.swift
+++ b/TablePro/Views/ERDiagram/ERDiagramNodeRenderer.swift
@@ -1,3 +1,4 @@
+import AppKit
 import SwiftUI
 
 /// Renders table nodes imperatively on a Canvas GraphicsContext.
@@ -10,6 +11,26 @@ enum ERDiagramNodeRenderer {
     private static let maxTableNameChars = 24
     private static let maxTypeChars = 18
 
+    private static var headerPointSize: CGFloat {
+        NSFont.preferredFont(forTextStyle: .caption1).pointSize
+    }
+
+    private static var iconPointSize: CGFloat {
+        NSFont.preferredFont(forTextStyle: .caption2).pointSize
+    }
+
+    private static var badgePointSize: CGFloat {
+        NSFont.preferredFont(forTextStyle: .caption2).pointSize * 0.75
+    }
+
+    private static var columnNamePointSize: CGFloat {
+        NSFont.preferredFont(forTextStyle: .caption1).pointSize * (11.0 / 12.0)
+    }
+
+    private static var columnTypePointSize: CGFloat {
+        NSFont.preferredFont(forTextStyle: .caption2).pointSize
+    }
+
     static func drawNode(
         context: inout GraphicsContext,
         node: ERTableNode,
@@ -44,7 +65,7 @@ enum ERDiagramNodeRenderer {
             ? String(node.tableName.prefix(maxTableNameChars)) + "\u{2026}"
             : node.tableName
         let headerText = Text(displayName)
-            .font(.system(size: 12 * scale, weight: .semibold, design: .monospaced))
+            .font(.system(size: Self.headerPointSize * scale, weight: .semibold, design: .monospaced))
         context.draw(
             context.resolve(headerText),
             at: CGPoint(x: rect.minX + headerTextXOffset, y: rect.minY + headerHeight / 2),
@@ -53,7 +74,7 @@ enum ERDiagramNodeRenderer {
 
         // Table icon
         let iconText = Text(Image(systemName: "tablecells"))
-            .font(.system(size: 10 * scale))
+            .font(.system(size: Self.iconPointSize * scale))
             .foregroundStyle(.secondary)
         context.draw(
             context.resolve(iconText),
@@ -77,15 +98,15 @@ enum ERDiagramNodeRenderer {
 
             // PK/FK badge
             if col.isPrimaryKey {
-                let badge = Text(Image(systemName: "key.fill")).font(.system(size: 8 * scale)).foregroundStyle(Color(nsColor: .systemYellow))
+                let badge = Text(Image(systemName: "key.fill")).font(.system(size: Self.badgePointSize * scale)).foregroundStyle(Color(nsColor: .systemYellow))
                 clipped.draw(clipped.resolve(badge), at: CGPoint(x: rect.minX + badgeXOffset, y: rowY), anchor: .center)
             } else if col.isForeignKey {
-                let badge = Text(Image(systemName: "link")).font(.system(size: 8 * scale)).foregroundStyle(Color(nsColor: .systemBlue))
+                let badge = Text(Image(systemName: "link")).font(.system(size: Self.badgePointSize * scale)).foregroundStyle(Color(nsColor: .systemBlue))
                 clipped.draw(clipped.resolve(badge), at: CGPoint(x: rect.minX + badgeXOffset, y: rowY), anchor: .center)
             }
 
             // Column name
-            let nameText = Text(col.name).font(.system(size: 11 * scale, design: .monospaced))
+            let nameText = Text(col.name).font(.system(size: Self.columnNamePointSize * scale, design: .monospaced))
             clipped.draw(
                 clipped.resolve(nameText),
                 at: CGPoint(x: rect.minX + columnNameXOffset, y: rowY),
@@ -97,7 +118,7 @@ enum ERDiagramNodeRenderer {
                 ? String(col.dataType.prefix(maxTypeChars)) + "\u{2026}"
                 : col.dataType
             let typeText = Text(displayType)
-                .font(.system(size: 10 * scale, design: .monospaced))
+                .font(.system(size: Self.columnTypePointSize * scale, design: .monospaced))
                 .foregroundStyle(.secondary)
             clipped.draw(
                 clipped.resolve(typeText),
diff --git a/TablePro/Views/Main/MainContentView.swift b/TablePro/Views/Main/MainContentView.swift
index 19528bff2..1959a7ae9 100644
--- a/TablePro/Views/Main/MainContentView.swift
+++ b/TablePro/Views/Main/MainContentView.swift
@@ -322,8 +322,8 @@ struct MainContentView: View {
             }
             .task { handleConnectionStatusChange() }
             .onReceive(
-                NotificationCenter.default.publisher(for: .connectionStatusDidChange)
-                    .filter { ($0.object as? UUID) == connection.id }
+                AppEvents.shared.connectionStatusChanged
+                    .filter { $0.connectionId == connection.id }
             ) { _ in
                 handleConnectionStatusChange()
             }
diff --git a/TablePro/Views/Results/DataGridCoordinator.swift b/TablePro/Views/Results/DataGridCoordinator.swift
index 44bf26860..8e28f8a87 100644
--- a/TablePro/Views/Results/DataGridCoordinator.swift
+++ b/TablePro/Views/Results/DataGridCoordinator.swift
@@ -1,4 +1,5 @@
 import AppKit
+import Combine
 import SwiftUI
 
 // MARK: - Coordinator
@@ -92,7 +93,7 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
     var overlayEditor: CellOverlayEditor?
 
     var settingsObserver: NSObjectProtocol?
-    var themeObserver: NSObjectProtocol?
+    var themeCancellable: AnyCancellable?
     private var lastDataGridSettings: DataGridSettings
 
     @Binding var selectedRowIndices: Set<Int>
@@ -179,16 +180,12 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
     }
 
     func observeThemeChanges() {
-        themeObserver = NotificationCenter.default.addObserver(
-            forName: .themeDidChange,
-            object: nil,
-            queue: .main
-        ) { [weak self] _ in
-            Task { @MainActor [weak self] in
+        themeCancellable = AppEvents.shared.themeChanged
+            .receive(on: RunLoop.main)
+            .sink { [weak self] _ in
                 guard let self, let tableView = self.tableView else { return }
                 Self.updateVisibleCellFonts(tableView: tableView)
             }
-        }
     }
 
     func observeTeardown(connectionId: UUID) {
@@ -230,9 +227,6 @@ final class TableViewCoordinator: NSObject, NSTableViewDelegate, NSTableViewData
         if let observer = settingsObserver {
             NotificationCenter.default.removeObserver(observer)
         }
-        if let observer = themeObserver {
-            NotificationCenter.default.removeObserver(observer)
-        }
         if let observer = teardownObserver {
             NotificationCenter.default.removeObserver(observer)
         }
diff --git a/TablePro/Views/Results/DataGridView.swift b/TablePro/Views/Results/DataGridView.swift
index 2f9d04128..e016b8055 100644
--- a/TablePro/Views/Results/DataGridView.swift
+++ b/TablePro/Views/Results/DataGridView.swift
@@ -363,10 +363,7 @@ struct DataGridView: NSViewRepresentable {
             NotificationCenter.default.removeObserver(observer)
             coordinator.settingsObserver = nil
         }
-        if let observer = coordinator.themeObserver {
-            NotificationCenter.default.removeObserver(observer)
-            coordinator.themeObserver = nil
-        }
+        coordinator.themeCancellable = nil
         coordinator.tableRowsController.detach()
     }
 
diff --git a/TablePro/Views/Results/JSONHighlightPatterns.swift b/TablePro/Views/Results/JSONHighlightPatterns.swift
index 2997daaa7..4b7f8471e 100644
--- a/TablePro/Views/Results/JSONHighlightPatterns.swift
+++ b/TablePro/Views/Results/JSONHighlightPatterns.swift
@@ -3,13 +3,21 @@
 //  TablePro
 
 import Foundation
+import os
+
+private let patternLogger = Logger(subsystem: "com.TablePro", category: "JSONHighlightPatterns")
+
+private func compileJSONRegex(_ pattern: String) -> NSRegularExpression {
+    if let regex = try? NSRegularExpression(pattern: pattern) {
+        return regex
+    }
+    patternLogger.fault("Failed to compile JSON highlight pattern: \(pattern, privacy: .public)")
+    return NSRegularExpression()
+}
 
-// Patterns are compile-time string literals — NSRegularExpression init cannot fail.
-// swiftlint:disable force_try
 internal enum JSONHighlightPatterns {
-    static let string = try! NSRegularExpression(pattern: "\"(?:[^\"\\\\]|\\\\.)*\"")
-    static let key = try! NSRegularExpression(pattern: "(\"(?:[^\"\\\\]|\\\\.)*\")\\s*:")
-    static let number = try! NSRegularExpression(pattern: "(?<=[\\s,:\\[{])-?\\d+\\.?\\d*(?:[eE][+-]?\\d+)?(?=[\\s,\\]}])")
-    static let booleanNull = try! NSRegularExpression(pattern: "\\b(?:true|false|null)\\b")
+    static let string = compileJSONRegex("\"(?:[^\"\\\\]|\\\\.)*\"")
+    static let key = compileJSONRegex("(\"(?:[^\"\\\\]|\\\\.)*\")\\s*:")
+    static let number = compileJSONRegex("(?<=[\\s,:\\[{])-?\\d+\\.?\\d*(?:[eE][+-]?\\d+)?(?=[\\s,\\]}])")
+    static let booleanNull = compileJSONRegex("\\b(?:true|false|null)\\b")
 }
-// swiftlint:enable force_try
diff --git a/TablePro/Views/RightSidebar/UnifiedRightPanelView.swift b/TablePro/Views/RightSidebar/UnifiedRightPanelView.swift
index 10897ccc3..e2ea61f0b 100644
--- a/TablePro/Views/RightSidebar/UnifiedRightPanelView.swift
+++ b/TablePro/Views/RightSidebar/UnifiedRightPanelView.swift
@@ -125,7 +125,7 @@ struct UnifiedRightPanelView: View {
 
     private func inspectorIcon(_ systemName: String) -> some View {
         Image(systemName: systemName)
-            .font(.system(size: 13, weight: .regular))
+            .font(.subheadline)
             .symbolRenderingMode(.hierarchical)
             .foregroundStyle(.secondary)
             .frame(maxWidth: .infinity, maxHeight: .infinity)
diff --git a/TablePro/Views/Settings/LicenseActivationSheet.swift b/TablePro/Views/Settings/LicenseActivationSheet.swift
index 5c69a234d..8decc7d98 100644
--- a/TablePro/Views/Settings/LicenseActivationSheet.swift
+++ b/TablePro/Views/Settings/LicenseActivationSheet.swift
@@ -72,9 +72,7 @@ struct LicenseActivationSheet: View {
                     Button("Cancel") {
                         dismiss()
                     }
-                    .font(.subheadline)
-                    .buttonStyle(.plain)
-                    .foregroundStyle(.secondary)
+                    .keyboardShortcut(.cancelAction)
                 }
             }
             .padding(.top, 20)
diff --git a/TablePro/Views/Sidebar/FileConflictDiffSheet.swift b/TablePro/Views/Sidebar/FileConflictDiffSheet.swift
index 198f9e66e..2c3b9387a 100644
--- a/TablePro/Views/Sidebar/FileConflictDiffSheet.swift
+++ b/TablePro/Views/Sidebar/FileConflictDiffSheet.swift
@@ -29,7 +29,8 @@ internal struct FileConflictDiffSheet: View {
             Divider()
             footer
         }
-        .frame(width: 760, height: 540)
+        .frame(minWidth: 600, idealWidth: 760, maxWidth: .infinity,
+               minHeight: 400, idealHeight: 540, maxHeight: .infinity)
     }
 
     private var header: some View {