feat(mcp): make sync opt-in and address review

Opt-in (mcpSyncEnabled, default OFF; routes 403 until on). Review fixes:
- codex TOML read/validated with smol-toml: CRLF, inline tables and
  command-less tables no longer yield a duplicate [mcp_servers.x]; the new
  text is re-parsed before writing
- null-prototype tables and own-key checks; unsafe names ignored at every level
- servers switched off in their own CLI (codex/opencode/antigravity) are not copied
- only CLIs that are installed or already have a config file take part
- files receiving env/headers are left 0600; symlinked configs are written through
- one apply at a time (409), unique tmp files cleaned on failure, failed status
- routes set real HTTP status codes; api-reference section; format type single-sourced

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/api-reference.md

@@ -713,6 +713,26 @@ Read and write the CLI registry (`docs/cli-registry.md`). Every **write** route
 | `PUT`    | `/api/clis/custom/:id`        | `{ label, shortBadge, binaries, argv, enabled? }`       | Replace an existing custom entry. An absent `enabled` keeps the entry's current state. `400` for a stock id, `404` for an unknown one. |
 | `DELETE` | `/api/clis/:id`               | none                                                    | Delete a custom entry. `400` for a stock id, `404` for an unknown one.                                  |
 
+## MCP server sync
+
+Copies MCP servers between the agent CLIs' own user-level config files (`docs/cli-registry.md`, "MCP server sync"). **Opt-in:** both routes answer `403 FORBIDDEN` while the synced `mcpSyncEnabled` setting is off (the default), and for a non-admin in multi-user mode, because the routes write files in the server user's home. A second `POST` while one is running answers `409 CONFLICT`.
+
+| Method | Path            | Body | Notes                                                                                                                   |
+| ------ | --------------- | ---- | ----------------------------------------------------------------------------------------------------------------------- |
+| `GET`  | `/api/mcp-sync` | none | Dry run. Same result shape as `POST`, with `applied: false`; nothing is written.                                        |
+| `POST` | `/api/mcp-sync` | none | Adds each server a CLI is missing to that CLI's config file. Never edits or removes a server. `500` on an unexpected error. |
+
+Result (`data`):
+
+- `applied` — `false` for the dry run.
+- `targets[]` — one per enabled CLI that declares an MCP config: `id`, `label`, `file`, `status`, `error?`, `servers` (names it already has), `added` (names added, or that would be), `skipped` (names its dialect cannot express, e.g. SSE for Codex and Antigravity).
+  - `status`: `ok`; `absent` (not installed and no config file, so not read or created); `unreadable` (the file exists but cannot be parsed safely, so it is not written); `failed` (a read or write error, the file may be unchanged).
+- `conflicts[]` — names defined differently by different CLIs. Existing definitions are kept; the first CLI's is copied where the name is missing.
+- `disabled[]` — names left out because every definition is switched off in its own CLI (codex `enabled = false`, opencode `enabled: false`, antigravity `disabled: true`).
+- `unsupported[]` — labels of enabled agent CLIs with no known MCP config file (nothing is guessed).
+
+The result carries server **names** only, never `env` values or `headers`. Each changed file keeps its previous content as `<file>.codeman-bak` (overwritten by each sync); a file that receives servers carrying `env` or `headers` is left mode `0600`.
+
 ## Voice dictation
 
 Browser dictation transcribed through this server's Claude Code login, i.e. the

docs/cli-registry.md

@@ -251,9 +251,9 @@ A module-level const freezes at first import, and the failure is asymmetric: a C
 
 ## MCP server sync
 
-`capabilities.mcpConfig` (`{ path, format }`, `path` relative to the home directory) names the file a CLI keeps its user-level MCP server list in and the dialect it is written in. `src/mcp-sync.ts` reads that list from every ENABLED CLI that declares one and adds any server a CLI is missing from the others; `GET`/`POST /api/mcp-sync` and Settings → Agents & CLIs → MCP servers drive it. Declared today for claude, gemini, codex, opencode and antigravity; every format was checked against what the CLI's own `mcp add` writes, except opencode's (documented, not installed to check). A CLI with no entry (pi, grok, omp, deepseek) is not guessed at: it is listed as `unsupported` in the result when enabled. Adding one is a registry entry plus a small adapter in `mcp-sync.ts`, and a verified fixture in `test/mcp-sync.test.ts`.
+`capabilities.mcpConfig` (`{ path, format }`, `path` relative to the home directory) names the file a CLI keeps its user-level MCP server list in and the dialect it is written in. `src/mcp-sync.ts` reads that list from every ENABLED CLI that declares one, and that is installed or already has the file (a CLI that is neither is reported `absent`, never created), and adds any server a CLI is missing from the others. It writes other tools' own config, so it is **opt-in**: `mcpSyncEnabled` (synced, default OFF) gates `GET`/`POST /api/mcp-sync` (403 while off) and the Settings → Agents & CLIs → MCP servers controls. Declared today for claude, gemini, codex, opencode and antigravity; every format was checked against what the CLI's own `mcp add` writes, except opencode's (documented, not installed to check). A CLI with no entry (pi, grok, omp, deepseek) is not guessed at: it is listed as `unsupported` in the result when enabled. Adding one is a registry entry plus a small adapter in `mcp-sync.ts`, and a verified fixture in `test/mcp-sync.test.ts`.
 
-Three rules the module keeps and the tests pin: it only ADDS (an existing server is never edited or removed, a same-name difference is reported as a conflict), it never writes a file it could not parse (opencode JSONC with comments), and its result carries server names only, never env values or headers. The schema restricts `path` to a home-relative path without `..`, since sync writes to it.
+The rules the module keeps and the tests pin: it only ADDS (a name already defined, in any shape, is never edited or removed; a same-name difference is reported as a conflict); a server switched off in its own CLI is not copied; it never writes a file it could not parse (opencode JSONC with comments, a TOML file with a duplicate table) and re-parses the new text before writing; codex TOML is read with a real parser (`smol-toml`), so CRLF files and inline tables are handled; names such as `__proto__` are ignored and every table keyed by an untrusted name has no prototype; a symlinked config is written through, not replaced; a file that receives `env`/`headers` is left `0600`; only one apply runs at a time; and its result carries server names only, never env values or headers. The schema restricts `path` to a home-relative path without `..`, since sync writes to it.
 
 ## See also
 

docs/wiki/HTTP-API.md

@@ -144,7 +144,7 @@ curl -s "$API/api/sessions" | jq '.data[].name'    # live sessions
 curl -s "$API/api/sessions/unified" | jq           # live + historical, deduped
 curl -s "$API/api/subagents" | jq                  # background agents
 curl -s "$API/api/search?q=deploy" | jq            # cross-session search
-curl -s "$API/api/mcp-sync" | jq                    # preview MCP server sync across enabled CLIs (names only)
+curl -s "$API/api/mcp-sync" | jq                    # preview MCP server sync (opt-in: 403 until mcpSyncEnabled is on)
 curl -s -X POST "$API/api/mcp-sync" | jq             # apply it: add missing servers to each CLI config, never edit/remove
 
 # with ID set to a session id: