feat: UX behavioral foundations + ux-audit command (v0.17.0.0) (#1000)

* feat: UX behavioral foundations — Krug's usability principles as shared design infrastructure

Add UX_PRINCIPLES resolver distilling Steve Krug's "Don't Make Me Think" into
actionable guidance for AI agents. Injected into all 4 design skills as a shared
behavioral foundation complementing the existing visual checklist (WHAT to check)
and cognitive patterns (HOW designers see) with HOW USERS ACTUALLY BEHAVE.

Methodology rewire: 6 Krug usability tests woven into existing design-review
phases — Trunk Test, 3-Second Scan, Page Area Test, Happy Talk Detection with
word count metric, Mindless Choice Audit, Goodwill Reservoir tracking with
visual dashboard. First-person narration mode for design-review output with
anti-slop guardrail.

Hard rules: 4 Krug always/never rules in DESIGN_HARD_RULES (placeholder-as-label,
floating headings, visited link distinction, minimum type size). Krug, Redish,
Jarrett added to plan-design-review references.

Token ceiling: gen-skill-docs.ts warns if any SKILL.md exceeds 100KB (~25K tokens).
Documented in CLAUDE.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: $B ux-audit command + snapshot --heatmap flag

New browse meta-command: ux-audit extracts page structure (site ID, navigation,
headings, interactive elements, text blocks) as structured JSON for agent-side
UX behavioral analysis. Pure data extraction — the agent applies the 6 usability
tests and makes judgment calls. Element caps: 50 headings, 100 links, 200
interactive, 50 text blocks.

New snapshot flag: -H/--heatmap accepts a JSON color map mapping ref IDs to
colors (green/yellow/red/blue/orange/gray). Extends existing snapshot -a
annotation system with per-ref colors instead of hardcoded red. Color whitelist
validation prevents CSS injection. Composable — any skill can use it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: update project documentation for v0.17.0.0

ARCHITECTURE.md: added {{UX_PRINCIPLES}} resolver to placeholder table.
VERSION: bumped to 0.17.0.0 for UX behavioral foundations release.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version and changelog (v0.17.0.0)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: adversarial review fixes for ux-audit and heatmap

Security:
- Remove live form value extraction from ux-audit (leaked input field values)
- Add ux-audit to PAGE_CONTENT_COMMANDS (untrusted content wrapping)

Correctness:
- Scope youAreHere selector to nav containers (was matching animation classes)
- Validate heatmap JSON is a plain object (string/array/null produced garbage)
- Use textContent instead of innerText for word count (avoids layout computation)
- Remove dead url variable and unused LINK_CAP constant

Found by Codex + Claude adversarial review.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -138,6 +138,11 @@ SKILL.md files are **generated** from `.tmpl` templates. To update docs:
 To add a new browse command: add it to `browse/src/commands.ts` and rebuild.
 To add a snapshot flag: add it to `SNAPSHOT_FLAGS` in `browse/src/snapshot.ts` and rebuild.
 
+**Token ceiling:** Generated SKILL.md files must stay under 100KB (~25K tokens).
+`gen-skill-docs` warns if any file exceeds this. If a skill template grows past the
+ceiling, consider extracting optional sections into separate resolvers that only
+inject when relevant, or making verbose evaluation rubrics more concise.
+
 **Merge conflicts on SKILL.md files:** NEVER resolve conflicts on generated SKILL.md
 files by accepting either side. Instead: (1) resolve conflicts on the `.tmpl` templates
 and `scripts/gen-skill-docs.ts` (the sources of truth), (2) run `bun run gen:skill-docs`