fix(trekplan): drop TaskCreate/TaskUpdate from the tool lists - measured dead weight

Claude Code 2.1.233 stopped offering the task/todo tools on Opus 4.8, Sonnet 5, Fable 5
and newer unless CLAUDE_CODE_ENABLE_TODO_TOOLS=1 is set. /trekplan still listed
TaskCreate and TaskUpdate in allowed-tools. So did the two orchestrator reference docs,
which mirror the command but are never spawned. No prose in any command calls either tool.

Runtime effect, measured BEFORE removal on CC 2.1.274, claude-opus-5, with
CLAUDE_CODE_ENABLE_TODO_TOOLS unset:
- Probe: a throwaway project command whose frontmatter is
  `allowed-tools: Read, TaskCreate, TaskUpdate`, run headless
  (`claude -p --output-format stream-json --verbose`).
- The session had 151 tools. The only Task* names among them were Task, TaskOutput and
  TaskStop; neither TaskCreate nor TaskUpdate was there.
- The command loaded (listed in slash_commands) and completed with subtype=success,
  is_error=false and 0 tool calls. The model reported the tool as not available.
- `claude plugin validate` does not flag the unknown names either: only the one
  accepted warning appears, before and after.
Verdict: harmless dead weight, no error anywhere, so this is a correctness-of-docs fix
rather than a runtime fix.

End-state gate D-05: open -> closed (defects 5 -> 4 of 7). Suite 1059 (1057/0/2), run
on a clean export of the index.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

agents/planning-orchestrator.md

@@ -3,7 +3,7 @@ name: planning-orchestrator
 description: Reference document, not a spawnable capability — documents the /trekplan planning workflow that runs inline in main context (full rationale, CC-2.1.172 history, and phase map in body).
 model: opus
 color: cyan
-tools: ["Read", "Glob", "Grep", "Write", "Edit", "Bash", "TaskCreate", "TaskUpdate"]
+tools: ["Read", "Glob", "Grep", "Write", "Edit", "Bash"]
 ---
 
 <!-- Phase mapping: orchestrator → command