feat(claude): advisor tool support, per session and as an App Settings default

Claude Code's advisor tool (code.claude.com/docs/en/advisor) lets the session's
main model consult a second, stronger model at decision points: before
committing to an approach, on a recurring error, and before declaring a task
done. Codeman can now start claude sessions with one.

- `advisorModel` field on POST /api/sessions, /api/quick-start and
  /api/ralph-loop/start (fable, opus, sonnet or a full model id in those
  families; haiku cannot advise and is refused). Stored on the session and
  persisted, so respawn, boot restore and reboot restore keep it. Remote and
  docker quick-starts refuse it, as they refuse effort.
- App Settings, Models, "Advisor" segment (Default / Sonnet / Opus / Fable),
  synced as `claudeAdvisorModel`. Run, resume and the Ralph wizard send it.
  Default sends nothing, leaving the CLI's own /advisor choice in charge.
- Carried as the `advisorModel` key in the launch's single --settings JSON,
  merged with ultracode and the statusLine exporter, never the --advisor
  flag: `claude --advisor haiku` exits 1 at launch, which would leave a dead
  pane on every respawn, while the settings key degrades to no advisor. A
  launch without an advisor is byte-identical to before.

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

CLAUDE.md

@@ -137,6 +137,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 - **Global regex `lastIndex`** — Shared `g`-flag patterns in loops must reset `lastIndex = 0` first, or use the `execPattern()` helper in `utils/regex-patterns.ts` (resets automatically)
 - **`envOverrides` flow `CLAUDE_CODE_*` / `OPENCODE_*` / `CODEX_*` / `GEMINI_*` / `GOOGLE_*` / `ANTIGRAVITY_*` / `PI_*` / `GROK_*` / `XAI_*` / `DSH_*` / `DEEPSEEK_*` env vars, plus exact-key `CLAUDE_CONFIG_DIR`** — Set via `POST /api/sessions { envOverrides }`, stored on `Session._envOverrides`, exported by `tmux-manager.buildEnvExports()` at spawn time, persisted in `SessionState.envOverrides`. **Do NOT** write these to `<case>/.claude/settings.local.json` — that's the old path and creates UI/disk drift. (`GOOGLE_*` is the deliberately-broad Vertex-AI namespace for Gemini — see Multi-CLI prefix discipline.) `CLAUDE_CONFIG_DIR` (#255, exact match via `ALLOWED_ENV_KEYS` in `schemas.ts`) points a session at a separate Claude account/config dir for per-client subscriptions; it persists to state.json (a path, not a secret; losing it on restart would silently switch accounts). ⚠️ A relocated config dir writes transcripts outside `~/.claude/projects`, so the response viewer, subagent windows, ultracode panel and Read My Mind capture go blind for that session unless the user symlinks `projects` back into the shared tree (`ln -s ~/.claude/projects <configDir>/projects`). ⚠️ It is also one of claude's `privilegedEnvKeys` (Custom Model Endpoint Profiles, since it can redirect a session's traffic same as any other injected var), so in multi-user mode setting it via `envOverrides` is admin-only, and a non-granted owner's already-persisted `CLAUDE_CONFIG_DIR` is stripped on reboot-restore — silently returning that session to the default Claude account rather than the one it was pointed at (see `session-env-clamp.ts`). → [architecture-invariants#per-session-env-overrides-exact-key-allowlist-and-claude_config_dir](docs/architecture-invariants.md#per-session-env-overrides-exact-key-allowlist-and-claude_config_dir)
 - **Effort is NOT an env var** — never carry effort as `CLAUDE_CODE_EFFORT_LEVEL`: the env var hard-locks effort and blocks in-session `/effort` switching (incl. ultracode). It flows as the dedicated `effort` payload field → `Session._effort` → `claude --effort <level>` for regular levels incl. `max` (the settings `effortLevel` key is `enum(["low","medium","high","xhigh"]).catch(undefined)` — `max` gets SILENTLY dropped there), or `claude --settings '{"ultracode":true}'` for ultracode (rejected by `--effort`). Both are soft defaults the user can override anytime. Legacy env-var entries are auto-migrated by the Session constructor and unset from tmux sessions in `applyEnvOverrides()`. See `buildEffortCliArgs()` in `session-cli-builder.ts`, tests in `test/effort-injection.test.ts`
+- **The advisor rides `--settings`, NEVER the `--advisor` flag**: Claude Code's advisor tool (a stronger model consulted at decision points, code.claude.com/docs/en/advisor) flows as the `advisorModel` payload field → `Session._advisorModel` (persisted, so respawn and reboot restore keep it) → the `advisorModel` key in the launch's ONE `--settings` JSON, merged with ultracode and the statusLine exporter by `buildAdvisorSettings()` (`session-cli-builder.ts`). ⚠️ The flag EXITS at launch on any pairing the CLI refuses (`claude --advisor haiku` exits 1, so does Fable before its usage-credit consent), which would leave a dead pane on every respawn; the settings key degrades to "no advisor" instead. ⚠️ `isAdvisorModel()` (fable/opus/sonnet aliases or full ids, no haiku) is also the injection guard for the single-quoted argument. Soft default: `/advisor` still switches it in-session. App Settings key `claudeAdvisorModel` (SYNCED, `''` = leave it to the CLI). Remote/docker quick-start refuses it, like `effort`. Tests: `test/advisor-model.test.ts`
 - **Model choice flows via `settings.local.json`, NOT `--model` or env** — the App Settings **Claude Model** picker (`claudeModel` in `settings.json`) is read by `session-ui.js` at session create (wins over the legacy 1M-Opus toggles `opusContext1m`/`opusContext1mEnabled`), sent as the `modelOverride` payload field, and `updateCaseModel()` (`hooks-config.ts`) writes/deletes the `model` key in `<case>/.claude/settings.local.json`. This is the intended exception to the envOverrides rule above: model legitimately lives in `settings.local.json` (a soft default — in-session `/model` still works); env vars do not
 - **Multi-CLI prefix discipline** — env-var prefix is CLI-specific (`CLAUDE_CODE_*` vs `OPENCODE_*` vs `CODEX_*` vs `GEMINI_*` vs `ANTIGRAVITY_*` vs `PI_*` vs `GROK_*` vs `DSH_*`) and the `ALLOWED_ENV_PREFIXES` allowlist in `schemas.ts` enforces this; non-prefix exceptions are exact keys in `ALLOWED_ENV_KEYS` (currently only `CLAUDE_CONFIG_DIR`), never a widened prefix. Gemini additionally allowlists the **broad `GOOGLE_*`** namespace (intentional: Vertex AI auth needs `GOOGLE_CLOUD_PROJECT`/`GOOGLE_APPLICATION_CREDENTIALS`/`GOOGLE_GENAI_USE_VERTEXAI`; it is the loosest allowlist entry, affecting only the user's own spawned CLI), and Grok allowlists **`XAI_*`** for the same vendor-namespace reason (`XAI_API_KEY` is grok's documented auth var). When adding a setting, decide which CLI(s) it applies to and gate the env export accordingly. Never blanket-forward all prefixes. ⚠️ Pi is the case that proves the rule: its ~34 provider keys (`ANTHROPIC_API_KEY`, `OPENAI_API_KEY`, `HF_TOKEN`, …) share NO prefix, and the allowlist is one GLOBAL list applied by a refine with no mode context, so admitting them for pi would widen it for every mode at once — they stay out, and pi users authenticate via `/login` or the server process's own env. ⚠️ DeepSeek repeats pi's lesson exactly: a dsh `settings.yaml` can nominate ANY env var as a provider credential (`apiKeyEnv`), so only the vendor namespaces `DSH_*` (launcher inputs incl. `DSH_PERMISSION_MODE`) and `DEEPSEEK_*` (`DEEPSEEK_API_KEY`/`DEEPSEEK_BASE_URL`) are admitted; foreign provider keys authenticate from dsh's own files or the server env. Resolver design pattern: `docs/opencode-integration.md`, `docs/pi-integration.md`, `docs/grok-integration.md`, `docs/deepseek-integration.md`
 - **Zod `.optional()` rejects `null`** — accepts `undefined` only. When the frontend builds a request body with `JSON.stringify`, an explicit `null` field is preserved on the wire and fails validation with `INVALID_INPUT`. Convert `null` → `undefined` before stringifying (e.g. `field: value ?? undefined`), or declare the schema `.nullish()`. This has caused real shipped bugs twice