chore: set up agent and contributor experience

.claude/settings.json

@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json.schemastore.org/claude-code-settings.json",
+  "hooks": {
+    "PostToolUse": [
+      {
+        "matcher": "Edit|MultiEdit|Write",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "jq -r '.tool_input.file_path // .tool_response.filePath // empty' | { read -r f; case \"$f\" in *.swift) command -v swiftformat >/dev/null && swiftformat \"$f\";; esac; }"
+          },
+          {
+            "type": "command",
+            "command": "jq -r '.tool_input.file_path // .tool_response.filePath // empty' | { read -r f; case \"$f\" in *.swift) if [ -f \"${CLAUDE_PROJECT_DIR:-.}/.swiftlint.yml\" ]; then command -v swiftlint >/dev/null && swiftlint lint --strict --quiet \"$f\"; fi;; esac; }"
+          }
+        ]
+      }
+    ]
+  }
+}

.editorconfig

@@ -0,0 +1,12 @@
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = space
+indent_size = 2
+
+[*.md]
+trim_trailing_whitespace = false

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,61 @@
+name: Bug Report
+description: Report incorrect behavior in KarrotCodableKit
+labels: ["Bug"]
+body:
+  - type: input
+    id: version
+    attributes:
+      label: KarrotCodableKit version
+      placeholder: "2.1.0"
+    validations:
+      required: true
+  - type: input
+    id: toolchain
+    attributes:
+      label: Swift / Xcode version
+      placeholder: "Swift 6.2 / Xcode 26.3"
+    validations:
+      required: true
+  - type: input
+    id: platform
+    attributes:
+      label: Platform and OS version
+      placeholder: "iOS 18.5 simulator"
+    validations:
+      required: false
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: What happened?
+      description: Describe the actual behavior. Include the full error output (e.g. the `DecodingError`) if any.
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Minimal reproducible code
+      description: The smallest type + decoding/encoding code that reproduces the issue.
+      render: swift
+    validations:
+      required: true
+  - type: textarea
+    id: json
+    attributes:
+      label: JSON payload
+      description: The JSON involved, if the bug is about decoding or encoding.
+      render: json
+    validations:
+      required: false
+  - type: textarea
+    id: expected
+    attributes:
+      label: Expected behavior
+    validations:
+      required: true
+  - type: checkboxes
+    id: checks
+    attributes:
+      label: Checklist
+      options:
+        - label: I searched existing issues and found no duplicate.
+          required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1 @@
+blank_issues_enabled: true

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,32 @@
+name: Feature Request
+description: Suggest new functionality for KarrotCodableKit
+labels: ["Feature"]
+body:
+  - type: textarea
+    id: motivation
+    attributes:
+      label: Problem / motivation
+      description: What problem would this solve? What are you trying to do that is currently hard or impossible?
+    validations:
+      required: true
+  - type: textarea
+    id: proposal
+    attributes:
+      label: Proposed API or solution
+      description: Sketch the API you have in mind, if any.
+      render: swift
+    validations:
+      required: false
+  - type: textarea
+    id: alternatives
+    attributes:
+      label: Alternatives considered
+    validations:
+      required: false
+  - type: checkboxes
+    id: contribution
+    attributes:
+      label: Contribution
+      options:
+        - label: I am willing to submit a PR for this.
+          required: false

.github/pull_request_template.md

@@ -13,3 +13,10 @@
 ## Review Notes
 <!-- Include any information that would help with the review. -->
 - 
+
+## Checklist
+<!-- Check what applies to this PR. -->
+- [ ] `swift test -c debug` and `swift test -c release` pass (test counts reported above)
+- [ ] Changes are covered by tests (for bug fixes: a regression test written first)
+- [ ] `swiftformat .` produces no diff
+- [ ] Docs updated if the public API changed

.swiftformat

@@ -0,0 +1,137 @@
+# SwiftFormat configuration for KarrotCodableKit.
+#
+# Based on the Karrot house style applied across this codebase in PR #30
+# (SwiftFormat 0.62.x). Uses an explicit rule whitelist: only the rules listed
+# under "rules" below run; everything else is disabled.
+#
+# `swiftformat .` must stay idempotent on a clean tree. Verify with:
+#   swiftformat --lint .
+#
+# Deliberate deviations from the house baseline, so the existing tree stays
+# untouched: isEmpty, wrapIfStatementBodies, and elseOnSameLine are not
+# enabled (tests intentionally assert `count == 0` for better failure
+# messages, and a few single-line if/else bodies are kept as written).
+
+# options
+--min-version 0.62.0
+--swift-version 6.2
+--language-mode 5
+--self remove # redundantSelf
+--import-grouping testable-bottom # sortedImports
+--trailing-commas multi-element-lists # trailingCommas
+--trim-whitespace always # trailingSpace
+--indent 2 #indent
+--ifdef no-indent #indent
+--indent-strings true #indent
+--wrap-arguments before-first # wrapArguments
+--wrap-parameters before-first # wrapArguments
+--wrap-collections before-first # wrapArguments
+--wrap-conditions before-first # wrapArguments
+--wrap-return-type never #wrapArguments
+--wrap-effects never #wrapArguments
+--closing-paren balanced # wrapArguments
+--call-site-paren balanced # wrapArguments
+--wrap-type-aliases before-first # wrapArguments
+--func-attributes prev-line # wrapAttributes
+--computed-var-attributes prev-line # wrapAttributes
+--stored-var-attributes preserve # wrapAttributes
+--complex-attributes prev-line # wrapAttributes
+--type-attributes prev-line # wrapAttributes
+--wrap-ternary before-operators # wrap
+--extension-acl on-declarations # extensionAccessControl
+--pattern-let inline # hoistPatternLet
+--property-types infer-locals-only # redundantType, propertyTypes
+--strip-unused-args closure-only # unusedArguments
+--type-blank-lines preserve # blankLinesAtStartOfScope, blankLinesAtEndOfScope
+--ranges preserve # spaceAroundOperators
+--some-any disabled # opaqueGenericParameters
+--single-line-for-each convert # preferForLoop
+--short-optionals always # typeSugar
+--semicolons never # semicolons
+--doc-comments preserve # docComments
+--max-width 120 # wrap
+--modifier-order private,fileprivate,internal,package,public,open,private(set),fileprivate(set),internal(set),package(set),public(set),open(set),override,final,dynamic,optional,required,convenience,indirect,isolated,nonisolated,nonisolated(unsafe),lazy,weak,unowned,unowned(safe),unowned(unsafe),static,class,borrowing,consuming,mutating,nonmutating,prefix,infix,postfix,async # modifierOrder
+
+# rules
+--rules anyObjectProtocol
+--rules blankLinesBetweenScopes
+--rules consecutiveSpaces
+--rules consecutiveBlankLines
+--rules duplicateImports
+--rules extensionAccessControl
+--rules environmentEntry
+--rules hoistPatternLet
+--rules indent
+--rules redundantParens
+--rules redundantReturn
+--rules redundantSelf
+--rules redundantType
+--rules redundantPattern
+--rules redundantGet
+--rules redundantFileprivate
+--rules redundantRawValues
+--rules redundantEquatable
+--rules sortImports
+--rules sortDeclarations
+--rules strongifiedSelf
+--rules trailingCommas
+--rules trailingSpace
+--rules linebreakAtEndOfFile
+--rules typeSugar
+--rules wrap
+--rules wrapMultilineStatementBraces
+--rules wrapArguments
+--rules wrapAttributes
+--rules wrapLoopBodies
+--rules braces
+--rules redundantClosure
+--rules redundantInit
+--rules redundantVoidReturnType
+--rules redundantOptionalBinding
+--rules redundantInternal
+--rules redundantVariable
+--rules unusedArguments
+--rules spaceInsideBrackets
+--rules spaceInsideBraces
+--rules spaceAroundBraces
+--rules spaceInsideParens
+--rules spaceAroundParens
+--rules spaceAroundOperators
+--rules enumNamespaces
+--rules blockComments
+--rules docComments
+--rules docCommentsBeforeModifiers
+--rules spaceAroundComments
+--rules spaceInsideComments
+--rules blankLinesAtStartOfScope
+--rules blankLinesAtEndOfScope
+--rules emptyBraces
+--rules andOperator
+--rules opaqueGenericParameters
+--rules genericExtensions
+--rules trailingClosures
+--rules sortTypealiases
+--rules preferForLoop
+--rules conditionalAssignment
+--rules wrapMultilineConditionalAssignment
+--rules void
+--rules blankLineAfterSwitchCase
+--rules consistentSwitchCaseSpacing
+--rules semicolons
+--rules propertyTypes
+--rules blankLinesBetweenChainedFunctions
+--rules emptyExtensions
+--rules preferCountWhere
+--rules preferFirstWhere
+--rules preferContains
+--rules swiftTestingTestCaseNames
+--rules modifiersOnSameLine
+--rules noForceTryInTests
+--rules noForceUnwrapInTests
+--rules redundantThrows
+--rules redundantAsync
+--rules noGuardInTests
+--rules redundantMemberwiseInit
+--rules redundantTypedThrows
+--rules redundantBreak
+--rules preferFinalClasses