fix(docs): the alias targets and effort defaults match the docs today (green)

Verified 2026-10-02 against code.claude.com/docs/en/model-config and
/sub-agents. On the Anthropic API opus -> Opus 5.5 and sonnet ->
Sonnet 5.5 (default effort medium), fable -> Fable 5.1 (default high).
Three more claims in the same section were false and are corrected:
an agent without effort: inherits the session level, not the model
default; MAX_THINKING_TOKENS=0 has no effect on Opus 5.5, Sonnet 5.5
or Fable; effort is capped by maxEffortLevel or an organization cap.
"Mythos-class" is replaced by the docs' own wording. History is
untouched (CHANGELOG, the measurement docs, the Path C line).

STATE said seven files but listed six; the red pin found exactly
these six. The end-state registry line names a CC changelog fact and
stays as history.

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

commands/trekbrief.md

@@ -404,15 +404,15 @@ The mapping table is canonical:
 - `low → {effort: low, model: sonnet}` (force sonnet for the low-cost path)
 - `standard → {effort: standard}` (model omitted; composition rule resolves via profile)
 - `high → {effort: high, model: opus}` (force opus for the high-confidence path)
-- `fable → {effort: high, model: fable}` (force Fable 5 for the max-quality path)
+- `fable → {effort: high, model: fable}` (force Fable 5.1 for the max-quality path)
 
 The fable tier reuses `effort: high` semantics — full swarm, contrarian
 always-on; `EFFORT_LEVELS` is unchanged (Voyage effort is orchestration
 shape, not model reasoning effort). Model reasoning effort is inherited from
-the session: Fable 5's default effort is `high`, NOT xhigh. To run xhigh, the
-operator sets it at session level via `/effort xhigh`, the `effortLevel`
-setting, or `CLAUDE_CODE_EFFORT_LEVEL` — switching model resets effort to the
-model default, so it does not follow the model.
+the session: Fable 5.1's default effort is `high`, NOT xhigh. To run xhigh, the
+operator chooses it explicitly via `/effort xhigh`, `--effort xhigh`, or
+`CLAUDE_CODE_EFFORT_LEVEL` — Claude Code saves effort per model, so a level
+saved for one model does not carry to another.
 
 ### Force-stop handling
 

commands/trekplan.md

@@ -549,7 +549,7 @@ Do NOT write this synthesis to disk. It is internal working context only.
 ## Phase 8 — Deep planning
 
 > **Schema-drift defense (sealed inline so this contract survives even when
-> `agents/planning-orchestrator.md` is not implicitly loaded by Opus 4.8).**
+> `agents/planning-orchestrator.md` is not implicitly loaded by the session model).**
 >
 > The plan you write MUST satisfy these regexes. The executor parses with
 > strict regex matching; any deviation breaks parsing and forces a re-plan.