fix(mcp-sync): route tests never follow COPILOT_HOME, and docs name Copilot (#581)

The route test cleared only the registry CLIs' relocation vars, so with
COPILOT_HOME exported it wrote its fixture into that real Copilot config.
It now clears the sync-only tools' vars too, and Copilot's install probe goes
through the test's own installed set instead of the machine's PATH.

Docs: CLAUDE.md, the API reference and the Settings reference name COPILOT_HOME
and the sync-only table; a missing comma in docs/cli-registry.md; the
mcp-sync.ts overview and the Sync confirm mention Copilot.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/api-reference.md

@@ -836,7 +836,7 @@ Result (`data`):
 - `targets[]` — one per enabled CLI that declares an MCP config, plus GitHub Copilot CLI (`id: "copilot"`, a sync-only target that is not a run mode): `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); `skipped` (the CLI's relocation env var, e.g. `CODEX_HOME`, is set to a relative path in the server's environment, so its file cannot be located safely and is neither read nor written); `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).
   - `error` says why a target is not `ok`. A parse failure is reported by position only (`not valid TOML (line 3, column 21)`, `not valid JSON`), never with text from the file.
-  - `file` honours each CLI's own relocation env var as the server process sees it (`CLAUDE_CONFIG_DIR`, `CODEX_HOME`, `XDG_CONFIG_HOME`, `GEMINI_CLI_HOME`); see `docs/cli-registry.md`.
+  - `file` honours each CLI's own relocation env var as the server process sees it (`CLAUDE_CONFIG_DIR`, `CODEX_HOME`, `XDG_CONFIG_HOME`, `GEMINI_CLI_HOME`, and `COPILOT_HOME` for the sync-only Copilot CLI); see `docs/cli-registry.md`.
 - `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).

docs/cli-registry.md

@@ -269,7 +269,7 @@ A module-level const freezes at first import, and the failure is asymmetric: a C
 
 **Tools that are not run modes.** GitHub Copilot CLI keeps an MCP list worth syncing but Codeman does not launch it, so it has no registry entry. `src/mcp-sync-targets.ts` declares such tools as plain data (`MCP_SYNC_ONLY_TOOLS`: id, label, config path, dialect, relocation var, the binary whose presence means "installed"). They join the registry CLIs as sync targets (listed after them, so a registry CLI's definition wins a same-name difference), under the same rules: installed or already configured, otherwise `absent`. Copilot's dialect is `copilot-json` (`~/.copilot/mcp-config.json`, relocated by `COPILOT_HOME`; checked against `copilot mcp add` 1.0.94): `mcpServers`, each entry with `tools` (`["*"]` = all), `type` `local` | `http` | `sse`, `command`/`args`/`env` or `url`/`headers`. `copilot mcp disable` does not mark the entry: it lists the name under `disabledMcpServers` in `settings.json` beside the config. Sync reads that list (never writes it) so a disabled server is not copied, and reports the target `unreadable` if `settings.json` is not valid JSON rather than guessing.
 
-`relocation` (`{ envVar, path }`) names the env var the CLI itself reads to move that file: claude `CLAUDE_CONFIG_DIR` (`.claude.json` under it), codex `CODEX_HOME` (`config.toml`), opencode `XDG_CONFIG_HOME` (`opencode/opencode.json`) gemini `GEMINI_CLI_HOME` (`.gemini/settings.json`) and, for the sync-only Copilot CLI, `COPILOT_HOME` (`mcp-config.json`); antigravity follows `$HOME` only, so it declares none. The var is read from the SERVER process env at call time, which is the env the CLIs Codeman spawns inherit. An absolute value moves the file to `<value>/<relocation.path>`, an empty one counts as unset (as it does for each CLI), and anything else reports the target `skipped` with the reason instead of writing a file the CLI never reads. A per-session relocation (a session's own `CLAUDE_CONFIG_DIR` in `envOverrides`) is not followed: the sync only knows the server's environment.
+`relocation` (`{ envVar, path }`) names the env var the CLI itself reads to move that file: claude `CLAUDE_CONFIG_DIR` (`.claude.json` under it), codex `CODEX_HOME` (`config.toml`), opencode `XDG_CONFIG_HOME` (`opencode/opencode.json`), gemini `GEMINI_CLI_HOME` (`.gemini/settings.json`) and, for the sync-only Copilot CLI, `COPILOT_HOME` (`mcp-config.json`); antigravity follows `$HOME` only, so it declares none. The var is read from the SERVER process env at call time, which is the env the CLIs Codeman spawns inherit. An absolute value moves the file to `<value>/<relocation.path>`, an empty one counts as unset (as it does for each CLI), and anything else reports the target `skipped` with the reason instead of writing a file the CLI never reads. A per-session relocation (a session's own `CLAUDE_CONFIG_DIR` in `envOverrides`) is not followed: the sync only knows the server's environment.
 
 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, and never file text: a parse failure is reported by line and column, not by the parser's message (smol-toml prints a code frame of the offending lines and V8's JSON errors quote source, either of which can hold a secret). The schema restricts `path` and `relocation.path` to a relative path without `..`, since sync writes to it.