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/features/mcp-oauth/callback-server.test.ts

@@ -5,29 +5,29 @@ const nativeFetch = Bun.fetch.bind(Bun)
 
 describe("findAvailablePort", () => {
   it("returns the start port when it is available", async () => {
-    //#given
+    // given
     const startPort = 19877
 
-    //#when
+    // when
     const port = await findAvailablePort(startPort)
 
-    //#then
+    // then
     expect(port).toBeGreaterThanOrEqual(startPort)
     expect(port).toBeLessThan(startPort + 20)
   })
 
   it("skips busy ports and returns next available", async () => {
-    //#given
+    // given
     const blocker = Bun.serve({
       port: 19877,
       hostname: "127.0.0.1",
       fetch: () => new Response(),
     })
 
-    //#when
+    // when
     const port = await findAvailablePort(19877)
 
-    //#then
+    // then
     expect(port).toBeGreaterThan(19877)
     blocker.stop(true)
   })
@@ -44,23 +44,23 @@ describe("startCallbackServer", () => {
   })
 
   it("starts server and returns port", async () => {
-    //#given - no preconditions
+    // given - no preconditions
 
-    //#when
+    // when
     server = await startCallbackServer()
 
-    //#then
+    // then
     expect(server.port).toBeGreaterThanOrEqual(19877)
     expect(typeof server.waitForCallback).toBe("function")
     expect(typeof server.close).toBe("function")
   })
 
   it("resolves callback with code and state from query params", async () => {
-    //#given
+    // given
     server = await startCallbackServer()
     const callbackUrl = `http://127.0.0.1:${server.port}/oauth/callback?code=test-code&state=test-state`
 
-    //#when
+    // when
     // Use Promise.all to ensure fetch and waitForCallback run concurrently
     // This prevents race condition where waitForCallback blocks before fetch starts
     const [result, response] = await Promise.all([
@@ -68,7 +68,7 @@ describe("startCallbackServer", () => {
       nativeFetch(callbackUrl)
     ])
 
-    //#then
+    // then
     expect(result).toEqual({ code: "test-code", state: "test-state" })
     expect(response.status).toBe(200)
     const html = await response.text()
@@ -76,25 +76,25 @@ describe("startCallbackServer", () => {
   })
 
   it("returns 404 for non-callback routes", async () => {
-    //#given
+    // given
     server = await startCallbackServer()
 
-    //#when
+    // when
     const response = await nativeFetch(`http://127.0.0.1:${server.port}/other`)
 
-    //#then
+    // then
     expect(response.status).toBe(404)
   })
 
   it("returns 400 and rejects when code is missing", async () => {
-    //#given
+    // given
     server = await startCallbackServer()
     const callbackRejection = server.waitForCallback().catch((e: Error) => e)
 
-    //#when
+    // when
     const response = await nativeFetch(`http://127.0.0.1:${server.port}/oauth/callback?state=s`)
 
-    //#then
+    // then
     expect(response.status).toBe(400)
     const error = await callbackRejection
     expect(error).toBeInstanceOf(Error)
@@ -102,14 +102,14 @@ describe("startCallbackServer", () => {
   })
 
   it("returns 400 and rejects when state is missing", async () => {
-    //#given
+    // given
     server = await startCallbackServer()
     const callbackRejection = server.waitForCallback().catch((e: Error) => e)
 
-    //#when
+    // when
     const response = await nativeFetch(`http://127.0.0.1:${server.port}/oauth/callback?code=c`)
 
-    //#then
+    // then
     expect(response.status).toBe(400)
     const error = await callbackRejection
     expect(error).toBeInstanceOf(Error)
@@ -117,15 +117,15 @@ describe("startCallbackServer", () => {
   })
 
   it("close stops the server immediately", async () => {
-    //#given
+    // given
     server = await startCallbackServer()
     const port = server.port
 
-    //#when
+    // when
     server.close()
     server = null
 
-    //#then
+    // then
     try {
       await nativeFetch(`http://127.0.0.1:${port}/oauth/callback?code=c&state=s`)
       expect(true).toBe(false)