chore(cleanup): R-b R3 — profiles, phase signals and the effort dialog removed, one fixed path per command

The four profiles, the resolver, the profile validator and docs/profiles.md go;
/trekbrief Phase 3.5 and the brief's phase_signals checks go (an older brief's
key is ignored); MANIFEST_PROFILE_DRIFT and profile_used go. Every Profile,
Composition rule, Sequencing gate and High-effort section leaves the commands.
Decision 209: /trekresearch runs the full swarm with contrarian-researcher as
wave 2 every run; /trekreview and the coordinator run all four passes with no
high-effort normalization. Voyage agents are spawned with no model (their own
model: opus applies); the two built-in spawns pass model "opus". --profile
stays in the parser as a retired flag that swallows its value. §Model & effort
moves to docs/architecture.md; the sequencing-gate eval case goes.

Files removed: 44 (43 from the R3 list + tests/commands/trekreview.test.mjs,
whose every test pinned removed text). Files edited: 43.
Tests: 2467 (2466 pass / 0 fail / 1 skipped) before, 2309 (2309 pass / 0 fail /
0 skipped) after. Durable check: all three groups green, none pending.

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

templates/trekbrief-template.md

@@ -24,21 +24,6 @@ ceremony: {small | bounded | architectural}
 # .git/info/exclude). The approval log is committed either way. Optional: absent
 # reads as local. Asked once per task in the /trekbrief question round.
 artifact_store: {git | local}
-# v5.1 — per-phase effort + model signal (Phase 3.5).
-# `effort` ∈ {low, standard, high}; `model` ∈ {sonnet, opus, fable} (v5.9).
-# Omit `model:` for `standard` so composition falls through to profile
-# resolver. Force-stop alternative is the commented
-# `phase_signals_partial: true` below (mutually exclusive with `phase_signals`).
-phase_signals:
-  - phase: research
-    effort: standard
-  - phase: plan
-    effort: standard
-  - phase: execute
-    effort: standard
-  - phase: review
-    effort: standard
-# phase_signals_partial: true   # uncomment to record force-stop instead of phase_signals
 ---
 
 # Task: {title}