feat(keyword-detector): add team mode keyword detection

Detects user invocations of team-mode work across English and Korean
('team mode', '팀 모드', '팀으로') and injects a concise English directive
instructing the LLM to orchestrate via team_* tools (team_create ->
team_task_create + team_send_message), forbidding delegate_task
substitution and fallbacks.

The Korean variants use a Hangul-syllable negative lookbehind (가-힣) so
that '스팀으로 게임 켜줘' does not falsely match '팀으로' and '스팀모드' does
not falsely match '팀모드'.

Follows the existing folder pattern (mode/default.ts + mode/index.ts)
shared by ultrawork/, search/, and analyze/. The hook orchestration in
hook.ts handles the new keyword type generically through the shared
KEYWORD_DETECTORS array, so existing guards (non-OMO agent skip,
non-main session filter, system-reminder strip, code-block strip) all
apply automatically.

Adds 7 regression tests covering English/Korean trigger forms, the
Hangul-prefix false-positive guard, the bare-'team' negative case, and
non-main-session filtering.

src/hooks/keyword-detector/AGENTS.md

@@ -4,7 +4,7 @@
 
 ## OVERVIEW
 
-8 files + 3 mode subdirs (~1665 LOC). Transform Tier hook on `messages.transform`. Scans first user message for mode keywords (ultrawork, search, analyze) and injects mode-specific system prompts.
+Transform Tier hook on `messages.transform`. Scans first user message for mode keywords (ultrawork, search, analyze, team) and injects mode-specific system prompts.
 
 ## KEYWORDS
 
@@ -13,6 +13,7 @@
 | `ultrawork` / `ulw` | `/\b(ultrawork|ulw)\b/i` | Full orchestration mode — parallel agents, deep exploration, relentless execution |
 | Search mode | `SEARCH_PATTERN` (from `search/`) | Web/doc search focus prompt injection |
 | Analyze mode | `ANALYZE_PATTERN` (from `analyze/`) | Deep analysis mode prompt injection |
+| Team mode | `TEAM_PATTERN` (from `team/`) | Forces orchestration via `team_*` tools when user invokes `team mode` / `팀 모드` / `팀으로`; instructs user to enable `team_mode.enabled` if tools are absent |
 
 ## STRUCTURE
 
@@ -31,10 +32,12 @@ keyword-detector/
 │   ├── index.ts
 │   ├── pattern.ts     # SEARCH_PATTERN regex
 │   └── message.ts     # SEARCH_MESSAGE
-└── analyze/
+├── analyze/
+│   ├── index.ts
+│   └── default.ts     # ANALYZE_PATTERN + ANALYZE_MESSAGE
+└── team/
     ├── index.ts
-    ├── pattern.ts     # ANALYZE_PATTERN regex
-    └── message.ts     # ANALYZE_MESSAGE
+    └── default.ts     # TEAM_PATTERN + TEAM_MESSAGE
 ```
 
 ## DETECTION LOGIC