fix(brainbar): make digest and ack truthful

REPORT.md

@@ -0,0 +1,37 @@
+## A1 live implementation
+
+Two implementations exist at base `cc1d21f66534747ee4a50367c290858972629a70`: Python `src/brainlayer/mcp/store_handler.py:88` (dispatched by `src/brainlayer/mcp/__init__.py:1482`) and Swift `brain-bar/Sources/BrainBar/BrainDatabase.swift:6457` (called by `brain-bar/Sources/BrainBar/MCPRouter.swift:993`). The live path is Swift: the running `/Applications/BrainBar.app/Contents/MacOS/BrainBarDaemon` owned `/tmp/brainbar.sock`, which is the socket default at `brain-bar/Sources/BrainBar/BrainBarServer.swift:181`; the stdio bridges connected to that socket. `brain-bar/Sources/BrainBarDaemon/BrainDatabase.swift` is a symlink to the same Swift source, not a third implementation.
+
+## A2 measured cutoff
+
+At base `cc1d21f66534747ee4a50367c290858972629a70`, a `tools/call` to `brain_digest` with exactly 701 characters returned success but the temporary database contained exactly 503 characters: the first 500 input characters plus `...`. Measured cutoff: 500. The RED assertion reported `brain_digest stored 503 characters from a 701-character input`; the defect is the prefix construction at `brain-bar/Sources/BrainBar/BrainDatabase.swift:6507` plus the normal success formatting at `brain-bar/Sources/BrainBar/MCPRouter.swift:1001`.
+
+## A3 stub count
+
+298 truncated stubs, six fewer than the unverified estimate of about 304.
+
+```sql
+SELECT COUNT(*) AS truncated_stubs FROM chunks WHERE created_at >= '2026-04-01' AND source = 'digest' AND length(content) >= 503 AND substr(content, -3) = '...';
+```
+
+Detection rule: rows created on/after 2026-04-01 with `source = 'digest'`, at least 503 characters, and a terminal `...`. This matches the base Swift behavior at `cc1d21f66534747ee4a50367c290858972629a70` (`brain-bar/Sources/BrainBar/BrainDatabase.swift:6507`): 500 content characters plus `...`, optionally preceded by a title. The query was run read-only with `sqlite3 "file:$HOME/.local/share/brainlayer/brainlayer.db?mode=ro"`.
+
+## A4 recoverable
+
+recoverable. The chunk rows contain only the stub (`source_file = 'brainbar-store'`, no original-content column), but matching stored prefixes and post-title body prefixes against pre-2026-08-01 local Claude/Codex/Cursor/Gemini transcripts located full tool-call inputs for 198 of 298 rows. The configured Google Drive `claude-jsonl` backup folder contains daily transcript archives through 2026-07-31, covering the source class for the remainder; the remaining 100 were not individually extracted from those archives during this task.
+
+## A5 fix chosen
+
+full digest — storage now receives the full input (with the optional title prepended), because the schema already accepts up to 200,000 characters and silent data loss is unnecessary.
+
+## B false ack
+
+Reproduction at base `cc1d21f66534747ee4a50367c290858972629a70`: `brain_ack({"agent_id":"cmuxlayer-owned-agent","seq":42})` returned `{"status":"acked"}` and created a BrainBar agent row with both cursors at 42. The cause is `brain-bar/Sources/BrainBar/BrainBarServer.swift:866`, which called an acknowledge path that auto-created unknown agents. The fix requires an existing BrainBar subscription; otherwise the MCP result has `isError: true`, text `No BrainBar subscription for agent: ...`, and no row is created. Dropped/missed messages: undetermined. The production DB has three acknowledged agent rows with zero subscription tags, but cursor state cannot show whether a caller discarded or overlooked an external cmux message; settling that requires the cmux inbox/consumer event history at each ack time.
+
+## tests
+
+RED on `cc1d21f66534747ee4a50367c290858972629a70`: `swift test --package-path brain-bar --filter 'MCPRouterTests.testBrainDigestStoresTheFullInputContent|SocketIntegrationTests.testMCPBrainAckRejectsAgentWithoutBrainBarSubscription'` executed 2 tests with 5 assertion failures: digest 503 versus 701, and false ack success plus created cursor row. GREEN after the fix: the same command executed 2 tests with 0 failures. Full suite command `swift test --package-path brain-bar` executed 842 tests with 10 skipped and 1 unrelated failure in `DashboardTests.testHeartbeatMarksStatsSnapshotPendingDuringCoalescedRefresh`; that test passed when rerun alone with `swift test --package-path brain-bar --filter 'DashboardTests.testHeartbeatMarksStatsSnapshotPendingDuringCoalescedRefresh'` (1 test, 0 failures). The changed suites passed in the full run: `MCPRouterTests` 74/74 and `SocketIntegrationTests` 21/21.
+
+## uncertainties
+
+The remaining 100 truncated inputs were not individually extracted from the Drive transcript archives. The full-suite dashboard timing failure is reproducible only in the full run so far and is outside Items A and B. Whether any caller missed an external message after a false ack is undetermined because no per-message cmux consumption history was available in the BrainLayer DB.

brain-bar/Sources/BrainBar/BrainBarServer.swift

@@ -863,6 +863,9 @@ final class BrainBarServer: @unchecked Sendable {
         }
 
         do {
+            guard try database.subscription(agentID: agentID) != nil else {
+                return toolErrorResponse(id: id, message: "No BrainBar subscription for agent: \(agentID)")
+            }
             try database.acknowledge(agentID: agentID, seq: seq)
             return jsonRPCTextResult(id: id, text: #"{"status":"acked"}"#)
         } catch {

brain-bar/Sources/BrainBar/BrainDatabase.swift

@@ -6504,9 +6504,8 @@ final class BrainDatabase: @unchecked Sendable {
         // Store the digest as a chunk
         let digestSummary = "Digest: \(entities.count) entities, \(urls.count) URLs, \(codeIds.count) code refs"
         let titledContent: String = {
-            let body = String(content.prefix(500)) + (content.count > 500 ? "..." : "")
-            if let title, !title.isEmpty { return "\(title)\n\n\(body)" }
-            return body
+            if let title, !title.isEmpty { return "\(title)\n\n\(content)" }
+            return content
         }()
 
         do {

brain-bar/Tests/BrainBarTests/MCPRouterTests.swift

@@ -1113,6 +1113,35 @@ No results found.
         XCTAssertNotNil(entity, "Digest-extracted entity should resolve via brain_entity lookup")
     }
 
+    func testBrainDigestStoresTheFullInputContent() throws {
+        let tempDB = NSTemporaryDirectory() + "brainbar-digest-full-content-\(UUID().uuidString).db"
+        defer { try? FileManager.default.removeItem(atPath: tempDB) }
+        let db = BrainDatabase(path: tempDB)
+        defer { db.close() }
+
+        let input = "DIGEST-CUTOFF " + String(repeating: "x", count: 677) + " FULL-TAIL"
+        XCTAssertEqual(input.count, 701)
+
+        let router = MCPRouter(profile: "full")
+        router.setDatabase(db)
+        let response = router.handle([
+            "jsonrpc": "2.0",
+            "id": 9,
+            "method": "tools/call",
+            "params": [
+                "name": "brain_digest",
+                "arguments": ["content": input]
+            ] as [String: Any]
+        ])
+
+        let result = try XCTUnwrap(response["result"] as? [String: Any])
+        XCTAssertNil(result["isError"] as? Bool)
+        let matches = try db.search(query: "DIGEST-CUTOFF", limit: 1)
+        let stored = try XCTUnwrap(matches.first?["content"] as? String)
+        XCTAssertEqual(stored.count, input.count, "brain_digest stored \(stored.count) characters from a \(input.count)-character input")
+        XCTAssertEqual(stored, input)
+    }
+
     func testBrainSubscribeToolIsServerHandled() throws {
         let router = MCPRouter(profile: "full")
         let request: [String: Any] = [

brain-bar/Tests/BrainBarTests/SocketIntegrationTests.swift

@@ -445,6 +445,34 @@ final class SocketIntegrationTests: XCTestCase {
         XCTAssertEqual(payload?["agent_id"] as? String, "agent-1")
     }
 
+    func testMCPBrainAckRejectsAgentWithoutBrainBarSubscription() throws {
+        _ = try sendMCPRequest([
+            "jsonrpc": "2.0", "id": 1, "method": "initialize",
+            "params": ["protocolVersion": "2024-11-05", "capabilities": [:] as [String: Any],
+                       "clientInfo": ["name": "ack-owner-check", "version": "1.0"]]
+        ])
+
+        let response = try sendMCPRequest([
+            "jsonrpc": "2.0",
+            "id": 5,
+            "method": "tools/call",
+            "params": [
+                "name": "brain_ack",
+                "arguments": [
+                    "agent_id": "cmuxlayer-owned-agent",
+                    "seq": 42
+                ] as [String: Any]
+            ]
+        ])
+
+        let result = try XCTUnwrap(response["result"] as? [String: Any])
+        let content = try XCTUnwrap(result["content"] as? [[String: Any]])
+        let text = try XCTUnwrap(content.first?["text"] as? String)
+        XCTAssertEqual(result["isError"] as? Bool, true)
+        XCTAssertTrue(text.contains("No BrainBar subscription"))
+        XCTAssertNil(try db.subscription(agentID: "cmuxlayer-owned-agent"))
+    }
+
     func testMatchingStorePushesChannelNotificationAndRequiresAckToClearUnread() throws {
         let subscriberFD = try connectClient()
         defer { close(subscriberFD) }