fix(newos4): pipe stage quoting, maintain ordering, help cost row, plan status (v4.6.131)

Four items closed in one batch; three ran as parallel subagents on disjoint files, the bundle was
rebuilt once by the parent (rebuild-bundles.py serialises the working tree, which carries other
sessions' work — see 161372f).

1. PIPE STAGES KEEP THEIR QUOTES. `js "a b".length | wc -c` reached eval as `a b.length` and printed
   a ReferenceError. terminal.js executePipeChain() now keeps `stages[i]` aligned 1:1 with
   `pipeParts[i]` (the `.filter(argv => argv.length > 0)` shifted the index; replaced by a lastStage
   scan + `if (argv.length === 0) continue`) and forwards the stage's own text to the dispatcher.
   The core path alone was dead code: ShellModule.init() replaces terminal.executePipeChain
   (shell.js:144), and that override is what runs in the browser (`executePipeChain.toString()`
   contained `cmdText.split`, not `lastStage`). Both now pass `cmdText`/`pipeParts[i]`.
   test-pipe-guard.js was rewritten for the new shape and now also asserts the shell override
   forwards raw text — the assertion that would have caught the shadowing. RED on HEAD: both flags
   false; GREEN now.

2. MAINTENANCE --fix CAN CLEAR ITS OWN WARN. check_index() ran before check_atlas(), which is what
   regenerates course/atlas.json, so --fix rebuilt modules-index.json from the stale atlas and the
   same WARN reappeared every run. check_atlas() now runs immediately before check_index().
   modules-index.json regenerated: cost/usage present, 349 commands, version 2026-10-29-atlas.

3. `cost` DOCUMENTED. modules/core/module-billing.js registers `cost [on|off]` (an alias of `usage`);
   help.html had no row. Added above the `usage` row. help coverage 362/363 -> 363/363.

4. SHIPPED PLANS STOP ASKING FOR A DECISION. The applier only flips review<->safe, so every executed
   review-gated plan kept counting as an open decision (5 of 5). newos4-feedback-collect.py now reads
   the body: a `## Status` / `## Implementation` heading followed by shipped|executed plus a version,
   commit or date is `status: done`; those stay in `plans` (visible as shipped) but leave
   plans_review and awaiting_decision. Counts: plans_review 5 -> 0, awaiting_decision 4 -> 1
   (the remaining one is a real open report, RPT-20261027-160751).
   admin/feedback.html read `it.status[0]`, which would render `d` for a string status; it now
   prefers `status_lines[0]`.

Also carried, authored by earlier uncommitted sessions and already live in the bundle (attributed,
not silently absorbed): modules/core/module-billing.js (new, BillingModule: cost/usage),
its CORE_FILES entry in scripts/rebuild-bundles.py, and the BillingModule registry entry in
terminal.js. The bundle was rebuilt from HEAD + this batch with ollama-manager.js taken from HEAD,
so another session's in-flight `_httpError` refactor is deliberately NOT in the shipped bundle
(grep -c _httpError core-bundle.js = 0).

Verification
  node modules/test/test-pipe-guard.js   -> {"empty":[],"blank":[],"classifyGuarded":true,"pipeGuarded":true,"shellForwardsRaw":true}
  node modules/test/test-parse-args.js   -> 28/28 pass
  maintained job                          -> node tests 21/21 pass
  scripts/newos4-maintain.py             -> maintenance result: OK (modules-index 349, help 363/363,
                                            changelog current v4.6.131)
  live v4.6.131 (real DOM, no print monkey-patch):
    js "a b".length | wc -c   -> 1        (js printed 3, one byte)
    js "a b".length           -> 3
    js "abc".toUpperCase()    -> ABC
    echo "two words"          -> two words
    node -e "import('fs')"    -> red error + Node-builtin hint
    js 6*7                    -> 42
    unhandledrejection        -> 0
  livePipeImpl: shell-override, livePipeForwardsRaw: true, costRegistered: true

0 files changed, 0 insertions, 0 deletions