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>

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog
 
+## [0.17.0.0] - 2026-04-14
+
+### Added
+- **UX behavioral foundations.** Every design skill now thinks about how users actually behave, not just how the interface looks. A shared `{{UX_PRINCIPLES}}` resolver distills Steve Krug's "Don't Make Me Think" into actionable guidance: scanning behavior, satisficing, the goodwill reservoir, navigation wayfinding, and the trunk test. Injected into /design-html, /design-shotgun, /design-review, and /plan-design-review. Your design reviews now catch "this navigation is confusing" problems, not just "the contrast ratio is 4.3:1."
+- **6 usability tests woven into design-review.** The methodology now runs the Trunk Test (can you tell what site this is, what page you're on, and how to search?), 3-Second Scan (what do users see first?), Page Area Test (can you name each section's purpose?), Happy Talk Detection with word count (how much of this page is "blah blah blah"?), Mindless Choice Audit (does every click feel obvious?), and Goodwill Reservoir tracking with a visual dashboard (what depletes the user's patience at each step?).
+- **First-person narration mode.** Design review reports now read like a usability consultant watching someone use your site: "I'm looking at this page... my eye goes to the logo, then a wall of text I skip entirely. Wait, is that a button?" With anti-slop guardrail: if the agent can't name the specific element, it's generating platitudes.
+- **`$B ux-audit` command.** Standalone UX structural extraction. One command extracts site ID, navigation, headings, interactive elements, text blocks, and search presence as structured JSON. The agent applies the 6 usability tests to the data. Pure data extraction with element caps (50 headings, 100 links, 200 interactive, 50 text blocks).
+- **`snapshot -H` / `--heatmap` flag.** Color-coded overlay screenshots. Pass a JSON map of ref IDs to colors (`green`/`yellow`/`red`/`blue`/`orange`/`gray`) and get an annotated screenshot with per-element colored boxes. Color whitelist prevents CSS injection. Composable: any skill can use it.
+- **Token ceiling enforcement.** `gen-skill-docs` now warns if any generated SKILL.md exceeds 100KB (~25K tokens). Catches prompt bloat before it degrades agent performance.
+
+### Changed
+- **Krug's always/never rules** added to the design hard rules: never placeholder-as-label, never floating headings, always visited link distinction, never sub-16px body text. These join the existing AI slop blacklist as mechanical checks.
+- **Plan-design-review references** now include Steve Krug, Ginny Redish (Letting Go of the Words), and Caroline Jarrett (Forms that Work) alongside Rams, Norman, and Nielsen.
+
 ## [0.16.4.0] - 2026-04-13
 
 ### Added