fix: the findings of the release review of 6.3.0

The review of v6.2.0..f669b87 (BLOCK: 1 BLOCKER, 12 MAJOR, 1 MINOR), each
fixed behind a test that failed first, or, for the two missing tests, a test
shown to fail on a stub of the branch it covers.

- Review steps appended by /trekexecute Phase 7.2 are held to the step rules
  on any plan version: plan-validator --steps-from <N> (on a plan below 1.8 a
  template review step validated and was executed).
- The guard refuses where no one can be asked also when its rules will not
  load; the wave merge path names that refusal instead of MERGE_REFUSED.
  Tests for the classifier-error refusal and post-approval-log's own check.
- release-check: the version files may change only in their version after
  the review (JSON compared without it), README diff lines are read inside
  hunks only, an unreadable diff is exit 2, and npm test runs without
  NODE_TEST_CONTEXT.
- What counts as a step of only tests: a note in parentheses is not a path,
  and a data file under specs/ is not a test. End-to-end: rides on the last
  step that builds behaviour (validator hint, trekplan, template).
- A removed line is cited as <rev>:<path>:<line> (findings-schema hint,
  trekreview re-ask).
- skill-lint counts a trailing newline as no line; regression-check takes
  commandEnv from lib/util/command-env.mjs; CLAUDE.md names four mode-read
  exemptions.
- /security-review, older than v6.2.0: the criteria runner refuses git
  --output, which writes a file.

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

templates/plan-template.md

@@ -75,7 +75,8 @@ own. Preparatory refactoring comes first, as its own steps. Every step has
 end to end (`End-to-end:`). The test for a behaviour belongs in the step that
 builds it: a step of only tests for behaviour an earlier step delivered passes
 at its start point and can never be proven red (the validator warns:
-`PLAN_STEP_TESTS_ONLY`).
+`PLAN_STEP_TESTS_ONLY`). So `End-to-end:` rides on the last step that builds
+behaviour, with its script in that step's `Files:`, not on a step of its own.
 
 Optional per-step fields: `Interface in:` (what the step consumes, and which
 earlier step or existing code produces it), `Interface out:` (what it produces