fix(#4213): keep STATE.md progress surfaces synchronized (#4231)

* fix(#4213): keep STATE.md progress surfaces synchronized

* fix(#4213): clamp the shared progress bar and keep bold-first priority, changeset + property tests

- formatProgressMachineSegment clamps through clampPercentFromFraction
  (ADR-3180 Decision 7 kernel) with a 0 floor, so a hand-edited
  out-of-range persisted percent renders a clamped bar instead of
  throwing RangeError on repeat() inside the write seam
- stateReplaceProgressPercent restores the #2177 bold-first priority:
  **Progress:** anywhere in the body wins; a plain ^Progress: line is
  the fallback, so free text starting with Progress: cannot capture
  the rewrite ahead of the real status line
- cross-reference comment names the three consumers and the
  cmdStateSync sanctioned exception (ADR-3408 §8.3)
- CONTEXT.md: applyPostSyncPreservation reconciliation documented in
  the STATE.md Transition Module entry
- property tests (never-throws/well-formed, idempotency, round-trip,
  bold-first) + two regression rows through the CLI

---------

Co-authored-by: Tom Boucher <trekkie@nomorestars.com>

.changeset/4213-progress-surfaces-sync.md

@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 4231
+---
+**`state` verbs keep the STATE.md body Progress bar in sync with frontmatter `progress.percent`** — 13 of 15 verbs rewrote the frontmatter percent while the body bar stayed stale (issue #4213: frontmatter 75, body bar still 50), so the two surfaces silently diverged on every record-session, add-decision and milestone switch. The bar is now rewritten through one shared helper on the write seam, keeping the bold `**Progress:**` status line the target even when a free-text line above it starts with `Progress:`, and an out-of-range persisted percent renders a clamped 0-100 bar instead of crashing the write. (#4213)