refactor: major codebase cleanup - BDD comments, file splitting, bug fixes (#1350)

* style(tests): normalize BDD comments from '// #given' to '// given'

- Replace 4,668 Python-style BDD comments across 107 test files
- Patterns changed: // #given -> // given, // #when -> // when, // #then -> // then
- Also handles no-space variants: //#given -> // given

* fix(rules-injector): prefer output.metadata.filePath over output.title

- Extract file path resolution to dedicated output-path.ts module
- Prefer metadata.filePath which contains actual file path
- Fall back to output.title only when metadata unavailable
- Fixes issue where rules weren't injected when tool output title was a label

* feat(slashcommand): add optional user_message parameter

- Add user_message optional parameter for command arguments
- Model can now call: command='publish' user_message='patch'
- Improves error messages with clearer format guidance
- Helps LLMs understand correct parameter usage

* feat(hooks): restore compaction-context-injector hook

- Restore hook deleted in cbbc7bd0 for session compaction context
- Injects 7 mandatory sections: User Requests, Final Goal, Work Completed,
  Remaining Tasks, Active Working Context, MUST NOT Do, Agent Verification State
- Re-register in hooks/index.ts and main plugin entry

* refactor(background-agent): split manager.ts into focused modules

- Extract constants.ts for TTL values and internal types (52 lines)
- Extract state.ts for TaskStateManager class (204 lines)
- Extract spawner.ts for task creation logic (244 lines)
- Extract result-handler.ts for completion handling (265 lines)
- Reduce manager.ts from 1377 to 755 lines (45% reduction)
- Maintain backward compatible exports

* refactor(agents): split prometheus-prompt.ts into subdirectory

- Move 1196-line prometheus-prompt.ts to prometheus/ subdirectory
- Organize prompt sections into separate files for maintainability
- Update agents/index.ts exports

* refactor(delegate-task): split tools.ts into focused modules

- Extract categories.ts for category definitions and routing
- Extract executor.ts for task execution logic
- Extract helpers.ts for utility functions
- Extract prompt-builder.ts for prompt construction
- Reduce tools.ts complexity with cleaner separation of concerns

* refactor(builtin-skills): split skills.ts into individual skill files

- Move each skill to dedicated file in skills/ subdirectory
- Create barrel export for backward compatibility
- Improve maintainability with focused skill modules

* chore: update import paths and lockfile

- Update prometheus import path after refactor
- Update bun.lock

* fix(tests): complete BDD comment normalization

- Fix remaining #when/#then patterns missed by initial sed
- Affected: state.test.ts, events.test.ts

---------

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>

src/tools/grep/downloader.test.ts

@@ -10,7 +10,7 @@ describe("findFileRecursive", () => {
   let testDir: string
 
   beforeEach(() => {
-    // #given - create temp directory for testing
+    // given - create temp directory for testing
     testDir = join(tmpdir(), `downloader-test-${Date.now()}`)
     mkdirSync(testDir, { recursive: true })
   })
@@ -23,57 +23,57 @@ describe("findFileRecursive", () => {
   })
 
   test("should find file in root directory", () => {
-    // #given
+    // given
     const targetFile = join(testDir, "rg.exe")
     writeFileSync(targetFile, "dummy content")
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "rg.exe")
 
-    // #then
+    // then
     expect(result).toBe(targetFile)
   })
 
   test("should find file in nested directory (ripgrep release structure)", () => {
-    // #given - simulate ripgrep release zip structure
+    // given - simulate ripgrep release zip structure
     const nestedDir = join(testDir, "ripgrep-14.1.1-x86_64-pc-windows-msvc")
     mkdirSync(nestedDir, { recursive: true })
     const targetFile = join(nestedDir, "rg.exe")
     writeFileSync(targetFile, "dummy content")
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "rg.exe")
 
-    // #then
+    // then
     expect(result).toBe(targetFile)
   })
 
   test("should find file in deeply nested directory", () => {
-    // #given
+    // given
     const deepDir = join(testDir, "level1", "level2", "level3")
     mkdirSync(deepDir, { recursive: true })
     const targetFile = join(deepDir, "rg")
     writeFileSync(targetFile, "dummy content")
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "rg")
 
-    // #then
+    // then
     expect(result).toBe(targetFile)
   })
 
   test("should return null when file not found", () => {
-    // #given - empty directory
+    // given - empty directory
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "nonexistent.exe")
 
-    // #then
+    // then
     expect(result).toBeNull()
   })
 
   test("should find first match when multiple files exist", () => {
-    // #given
+    // given
     const dir1 = join(testDir, "dir1")
     const dir2 = join(testDir, "dir2")
     mkdirSync(dir1, { recursive: true })
@@ -81,23 +81,23 @@ describe("findFileRecursive", () => {
     writeFileSync(join(dir1, "rg"), "first")
     writeFileSync(join(dir2, "rg"), "second")
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "rg")
 
-    // #then
+    // then
     expect(result).not.toBeNull()
     expect(result!.endsWith("rg")).toBe(true)
   })
 
   test("should match exact filename, not partial", () => {
-    // #given
+    // given
     writeFileSync(join(testDir, "rg.exe.bak"), "backup file")
     writeFileSync(join(testDir, "not-rg.exe"), "wrong file")
 
-    // #when
+    // when
     const result = findFileRecursive(testDir, "rg.exe")
 
-    // #then
+    // then
     expect(result).toBeNull()
   })
 })