enhance(#2401): ground verify-command paths and inherit prior-phase commands (#3678)

* feat(#2401): ground <automated> verify-command paths and inherit prior-phase commands

Adds a deterministic resolvability probe over each PLAN.md <automated> verify
command and surfaces the nearest prior phase's proven commands to the planner
at every context window.

- src/verify-command-grounding.cts: recognizer (not a shell interpreter) that
  grounds a leading cd <literal> chain and npm --prefix <literal>, and reports
  unresolvable rather than guessing. Never executes command text.
- gsd-tools check verify-command-paths <N>: per-phase probe, wired into
  plan-phase.md before the plan-check pass.
- init.plan-phase gains prior_verify_commands, ungated by context_window.
- gsd-plan-checker: new Verify Command Path Resolvability dimension that
  reports the failing target and never prescribes a replacement.

Also fixes first-match-wins prefix bucketing in scripts/lint-test-file-count.cjs
(readdir order is not stable across platforms, so a module whose name extends
another's with a hyphen bucketed differently on Linux than on macOS).

Closes #2401

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

* fix(#2401): ground the canonical --prefix form, quoted paths, and absolute cd resets

Independent review found three defects in the recognizer:

- npm --prefix DIR run SCRIPT never reached the script-existence check,
  because the pattern required npm and run to be adjacent. That is the
  form the docs tell planners to prefer, so script_missing never fired
  for it. The prefix flag and its value are now stripped before matching.
- --prefix captured with \S+, so a quoted path containing a space was
  truncated to a stray opening quote and reported as a missing directory
  - a false blocker, worse than the bug this feature fixes. The capture
  is now quote-aware.
- A chained cd whose later segment was absolute concatenated instead of
  resetting, producing a nonsense path and another false blocker. The
  fold now resets on an absolute segment.

Also replaces the bespoke phase-directory regex with the canonical
phase-id helpers. Real phase directories are NN-slug, not phase-N-slug,
so the prior-command harvest matched nothing outside its own fixtures
and the planner-inheritance half of this feature was dead code.

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

* refactor(#2401): source task blocks from the canonical sectionizer

The module carried its own copy of the <task>-block grammar - a fourth
hand-rolled mirror of the one markdown-sectionizer owns. verify.cts keeps
its copy only because it needs the type= attribute the canonical helper
discards; this module never reads that attribute, so it can share the
owner outright instead of adding a test around a copy.

extractAutomatedCommands now takes task bodies from extractTaggedBlocks
and the out-of-task remainder from stripTaggedBlocks. A task-grammar
parity test pins the attributed task-name set against the canonical
helper across six awkward task shapes.

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

* fix(#2401): extract agent-file overflow to references and repair the property arbitrary

The remote matrix run came back red with 19 failures, four root causes:

- agents/gsd-plan-checker.md and agents/gsd-planner.md both blew the
  49152 agent cap. Their bodies move to gsd-core/references/, leaving
  @-reference stubs, per the documented overflow pattern.
- The new checker dimension invoked gsd_run before the canonical
  preamble that defines it. The call is deleted outright: plan-phase.md
  already runs the probe and hands the result in as {VERIFY_PATHS}, so
  the dimension consumes that rather than re-running anything.
- fc.fullUnicodeString does not exist in fast-check 4.8.0. Replaced with
  fc.string({ unit: 'binary' }), which covers the same 0000-10FFFF range.
- Three runtime-loaded files grew; acknowledged in the existing ack
  fragments that already own those bare filenames, since two ack sources
  may never name the same path.

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

* test(#2401): regenerate golden install-tree fixtures for the new references

Adding two files under gsd-core/references/ changes what the installer
emits into every runtime's tree, so all 19 golden install-parity
fixtures went stale. Regenerated with npm run gen:install-tree; the
delta is exactly the two new reference paths per runtime, no removals.

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

* chore(#2401): backfill changeset pr number to 3678

* fix(#2401): treat ~ as a home expansion only at the start of a path

Windows CI caught this on both shards; the Linux-only remote matrix
cannot see it. The dynamic-path refusal rejected ~ anywhere, and a
GitHub Windows runner's tmpdir is an 8.3 short name -
C:\Users\RUNNER~1\AppData\Local\Temp - so a valid absolute Windows
path came back unresolvable/dynamic_path.

This was a production bug, not a test artifact: any Windows user whose
project path carries an 8.3 short name, or any literal ~, silently lost
the probe entirely - every command degrading to unresolvable with no
explanation.

~ is a home expansion only at the start of a path; elsewhere it is an
ordinary literal. The check is now split: $, backtick, *, ? and newline
stay refused anywhere (substitution and globs, and the glob characters
are illegal in Windows path components regardless), while ~ is refused
only leading, tolerating one leading quote since the check runs before
quote stripping.

The prior tests only caught this on Windows because only Windows puts a
~ in tmpdir. Four new tests pin it on every platform via a fixture
directory literally named RUNNER~1.

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

---------

Co-authored-by: sim <sim@local>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

agents/gsd-plan-checker.md

@@ -715,6 +715,11 @@ issue:
 2. For each `<automated>` block containing `2>/dev/null || echo` where the result feeds a `[ "$VAR" = ... ]` comparison: BLOCKER.
 3. For each `<automated>` block asserting a specific numeric count not cited as measured in this plan: WARNING.
 
+## Dimension: Verify Command Path Resolvability (#2401)
+
+**Question:** Does each `<automated>` command's target resolve? Consume the supplied
+`{VERIFY_PATHS}` probe, never re-run/hand-reason it: @gsd-core/references/verify-command-path-resolvability.md
+
 ## Dimension: Numeric/Factual Claim Authority (#1480)
 
 **Rule:** RESEARCH.md is produced at research time and may be stale. Numeric claims (test counts, file counts, version numbers) and factual state claims ("feature X is implemented") in RESEARCH.md may not reflect the current codebase. The plan may be more current. RESEARCH.md is authoritative for architectural decisions and constraints — not for measurements.

agents/gsd-planner.md

@@ -190,6 +190,8 @@ Every task has four required fields:
 
 **Nyquist Rule:** Every `<verify>` includes `<automated>`. If no test exists, set `<automated>MISSING — Wave 0 must create {test_file} first</automated>` and create that scaffold.
 
+**Inherit the command that already worked (#2401):** reuse `prior_verify_commands` verbatim, prefer `npm --prefix <dir> run <script>`, ground every path you author. @gsd-core/references/planner-verify-command-grounding.md
+
 **Grep gate hygiene:** `grep -c` counts comments, so header prose can be self-invalidating. Use `grep -v '^#' | grep -c token`. Bare `== 0` gates on unfiltered files are forbidden.
 
 <comment_text_discipline>