feat: add manual export provider

TASKS.md

@@ -677,6 +677,36 @@ Status: ✅ Complete
 
 ---
 
+### Task 8.0 — Implement ReviewRequest and Manual Export Provider
+
+Add a zero-API-cost Manual Export provider that generates copy/paste-ready prompts for ChatGPT Web (https://chatgpt.com).
+
+**Files created:**
+- `src/providers/manual-export.js` — Manual export provider implementing `{ send(request, config) => Promise<{ content: string }> }`
+- `test/providers/manual-export.test.js` — 56 tests covering structure, tool detection, unicode, long prompts, edge cases, repeatability
+
+**Files modified:**
+- `src/providers/factory.js` — Added `"manual"` to SUPPORTED_PROVIDERS whitelist
+- `.env.example` — Documents `CHATGPT_MCP_PROVIDER=manual` option
+- `README.md` — Documents manual provider in Architecture table
+- `ARCHITECTURE.md` §12 — Already lists `"manual"` as supported provider
+
+**What it provides:**
+- Provider receives `{ prompt, input }` from the ReviewRequest pattern
+- Wraps the pre-built prompt in a box-delimited copy/paste format for ChatGPT Web
+- Uses `https://chatgpt.com` (not `https://chat.openai.com`)
+- Detects tool name from input fields (debug_issue, review_code, architecture_review, review_plan, ask_chatgpt)
+- Adds prompt length metadata and advisory footer
+- Warns on prompts over 30k characters
+- Zero API calls — purely cosmetic wrapping
+
+**Tests added:** 56 new tests in manual-export.test.js + 9 in factory.test.js for manual provider
+**Total test count:** 644 passing across 21 test files, zero regressions
+
+Status: ✅ Complete
+
+---
+
 ## Completion Summary
 
 | Phase | Description | Status |
@@ -689,5 +719,6 @@ Status: ✅ Complete
 | 5 | MCP Server and Registration | ✅ Complete (5 tools registered) |
 | 6 | Provider Abstraction | ✅ Complete (factory + adapter) |
 | 7 | Integration and Tests | ✅ Complete (579 tests across 20 files) |
+| 8 | Manual Export Provider | ✅ Complete (Task 8.0, 644 tests across 21 files) |
 
-**Total:** All planned MVP tasks complete. 579 passing tests, zero regressions, all docs updated.
+**Total:** All planned MVP tasks complete. 644 passing tests, zero regressions, all docs updated.