fix(plan): execute hands the plan to /trekexecute instead of building it in the planning session

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

commands/trekplan.md

@@ -1126,13 +1126,13 @@ Present a summary to the user:
 You can:
 - Say which open minors to fix ("fix 1 and 3")
 - Ask questions or request changes to refine the plan
-- Say **"execute"** to start implementing   ← only when the gate exited 0
+- Say **"execute"** for the `/trekexecute` line to run   ← only when the gate exited 0
 - Say **"save"** to keep the plan for later
 ```
 
 When the gate exited 1, replace the "execute" line with
-`Execution is blocked: {the gate's reasons}` and do not start implementing,
-whatever is said next, until the gate exits 0.
+`Execution is blocked: {the gate's reasons}` and do not print the `/trekexecute`
+line, whatever is said next, until the gate exits 0.
 
 **What counts as approval.** "Execute", "go" or "start" (or the plan-mode
 approval below) approves the plan. A hedged reply — "sounds good", "looks
@@ -1172,7 +1172,8 @@ plan-approval prompt:
 3. **Approved:** the session leaves plan mode. Copy the plan file to the plan
    destination from Phase 3, then run the gate on the destination — it must
    exit 0 again, which also proves the copy is the reviewed text. Then
-   continue with the operator's choice (Phase 11).
+   print the `/trekexecute` line (Phase 11) and stop — leaving plan mode is
+   not an order to implement.
 4. **"No, keep planning":** revise per the operator's words, run one Phase 9
    round, and present again from step 1.
 
@@ -1260,15 +1261,16 @@ Confirm the plan and brief file locations and exit.
 
 ### "execute" / "go" / "start"
 
-Begin implementing the plan step by step in this session. Follow the plan exactly.
-Mark each step complete as you go.
+Do not implement in this session. Print the line the operator gives
+`/trekexecute` — `/trekexecute --project {project_dir}`, or
+`/trekexecute {plan_path}` without a project directory — and stop.
+`/trekexecute` is what checks the plan's approval (K2), locks the tests, runs
+one step helper per step and the review.
 
 ### "execute with team" / "team"
 
-There is no team path. Tell the user that parallel team execution is not available
-from `/trekplan`, then proceed exactly as for "execute" (sequential, in this
-session). Parallel implementation is `--decompose` followed by `/trekexecute`'s
-multi-session waves.
+There is no team path. Print the same `/trekexecute` line and stop; parallel
+work is `--decompose` followed by `/trekexecute`'s session orders.
 
 ## Phase 12 — Session tracking