fix(metis): switch primary model to claude-sonnet-4-6 + correct AGENTS.md inaccuracies

Source code change:
- src/shared/model-requirements.ts: prepend claude-sonnet-4-6 to metis fallback
  chain so Sonnet becomes the default. Opus 4.7 max remains as the immediate
  fallback for callers who want extra reasoning.
- src/shared/model-requirements.test.ts: update assertion to expect Sonnet
  primary + Opus secondary.

AGENTS.md accuracy fixes (verified against source):
- Agent modes: Sisyphus/Hephaestus are 'primary' (not 'all'); Sisyphus-Junior
  is 'subagent' (not 'all'). Confirmed via 'const MODE: AgentMode = ...' in
  each agent file. Also clarified Prometheus has no agentSources factory and
  is built via buildPrometheusAgentConfig.
- Sisyphus fallback chain: corrected order to kimi-k2.6 → k2p5 → kimi-k2.5
  → gpt-5.5 medium → glm-5 → big-pickle (was missing kimi-k2.5).
- Librarian/Explore: added missing minimax-m2.7 step between -highspeed and
  claude-haiku-4-5.
- Metis chain: removed fictitious gemini-3.1-pro entry.
- Sisyphus-Junior chain: spelled out the actual fallback (was 'user-configurable').
- Temperatures: Sisyphus/Hephaestus do not set explicit temperature (model
  default); Sisyphus-Junior is 0.1 via SISYPHUS_JUNIOR_DEFAULTS.
- Quick category default: gpt-5.4-mini (not gpt-5.4-mini-fast).

Team-mode corrections:
- Eligibility registry has 3 verdicts: eligible (sisyphus, atlas, sisyphus-junior),
  conditional (hephaestus — needs D-36 teammate permission), hard-reject
  (oracle, librarian, explore, multimodal-looker, metis, momus, prometheus).
- Schema has 11 fields, not 4: added max_messages_per_run, max_wall_clock_minutes,
  max_member_turns, base_dir, message_payload_max_bytes, recipient_unread_max_bytes,
  mailbox_poll_interval_ms.
- Hooks: 'team-session-events' is 4 sub-handlers in src/plugin/event.ts
  (team-idle-wake-hint, team-lead-orphan-handler, team-member-error-handler,
  team-member-status-handler), not a single Continuation-tier hook.
- Tier counts now show base + team-mode: ToolGuard 14/15, Transform 5/7.
- Total: 52 base hooks, 59 with team-mode.

Doc cascade for the Metis change:
- docs/guide/orchestration.md, agent-model-matching.md, installation.md
- docs/reference/configuration.md, features.md

src/config/AGENTS.md

@@ -11,11 +11,11 @@
 ```
 config/schema/
 ├── oh-my-opencode-config.ts    # ROOT: composes all sub-schemas
-├── agent-names.ts              # BuiltinAgentNameSchema (10) + sisyphus-junior
+├── agent-names.ts              # BuiltinAgentNameSchema enum (11 names: sisyphus, hephaestus, prometheus, oracle, librarian, explore, multimodal-looker, metis, momus, atlas, sisyphus-junior)
 ├── agent-overrides.ts          # AgentOverrideConfigSchema (21 fields per agent)
 ├── agent-definitions.ts        # custom agent definition schema
 ├── categories.ts               # 8 built-in + custom categories
-├── hooks.ts                    # HookNameSchema (50+ hooks)
+├── hooks.ts                    # HookNameSchema (53 enum values; `team-tool-gating` is the only team-* one in schema — others are wired by direct config gates)
 ├── skills.ts                   # SkillsConfigSchema (sources, paths, recursive)
 ├── commands.ts                 # BuiltinCommandNameSchema
 ├── experimental.ts             # Feature flags incl plugin_load_timeout_ms (min 1000), task_system, max_tools
@@ -46,22 +46,30 @@ config/schema/
 
 `$schema`, `new_task_system_enabled`, `default_run_agent`, `disabled_mcps`, `disabled_agents`, `disabled_skills`, `disabled_hooks`, `disabled_commands`, `disabled_tools`, `hashline_edit`, `agents`, `categories`, `claude_code`, `sisyphus_agent`, `comment_checker`, `experimental`, `auto_update`, `skills`, `ralph_loop`, `background_task`, `notification`, `babysitting`, `git_master`, `browser_automation_engine`, `websearch`, `tmux`, `sisyphus`, `start_work`, `_migrations`, `model_fallback`, `model_capabilities`, `openclaw`, `mcp_env_allowlist`, `keyword_detector`, **`team_mode`**, `runtime_fallback`, `dynamic_context_pruning`.
 
-## TEAM_MODE SCHEMA
+## TEAM_MODE SCHEMA (11 fields)
 
 ```jsonc
 {
   "team_mode": {
-    "enabled": false,                  // gate for 12 team_* tools and conditional hooks
-    "max_parallel_members": 4,         // concurrent active members
-    "max_members": 8,                  // hard cap on team size
-    "tmux_visualization": false        // render tmux pane layout for the team
+    "enabled": false,                       // gate for 12 team_* tools and conditional hooks
+    "tmux_visualization": false,            // render tmux pane layout for the team
+    "max_parallel_members": 4,              // 1..8 concurrent active members
+    "max_members": 8,                       // 1..8 hard cap on team size
+    "max_messages_per_run": 10000,          // ≥1
+    "max_wall_clock_minutes": 120,          // ≥1
+    "max_member_turns": 500,                // ≥1
+    "base_dir": null,                       // override of ~/.omo/teams or <project>/.omo/teams
+    "message_payload_max_bytes": 32768,     // ≥1024
+    "recipient_unread_max_bytes": 262144,   // ≥1024
+    "mailbox_poll_interval_ms": 3000        // ≥500
   }
 }
 ```
 
 When `enabled: true`:
-- 12 `team_*` tools register
-- 4 team-mode hooks activate (status injector, mailbox injector, session events, tool gating)
+- 12 `team_*` tools register (`tool-registry.ts` `teamModeToolsRecord`)
+- 3 team-mode hooks register conditionally: `team-mode-status-injector` + `team-mailbox-injector` (Transform tier) and `team-tool-gating` (Tool Guard tier)
+- 4 team-session-event handlers register in `src/plugin/event.ts`: `team-idle-wake-hint`, `team-lead-orphan-handler`, `team-member-error-handler`, `team-member-status-handler`
 - `team-mode` built-in skill loads
 - Doctor check `cli/doctor/checks/team-mode.ts` runs