Add v0.6.0: full skill/agent QA pass, 3 new agents tested, template cleanup

Skills fixed: sprint-status (stale escalation, threshold), retrospective
(existing file detection, missing data fallback), changelog (misc category,
task-ref count), patch-notes (BLOCKED on missing changelog, tone/template
paths), story-readiness (Phase 0 mode resolution, QL-STORY-READY gate),
art-bible, brainstorm, design-system, ux-design, dev-story, story-done,
create-architecture, create-control-manifest, map-systems, propagate-design-change,
quick-design, prototype, asset-spec.

Agents fixed: all 4 directors (gate verdict token format), engine-programmer,
ui-programmer, tools-programmer, technical-artist (engine version safety),
gameplay-programmer (ADR compliance), godot-gdextension-specialist (ABI warning),
systems-designer (escalation path to creative-director), accessibility-specialist
(model, tools, WCAG criterion format, findings template), live-ops-designer
(escalation paths, battle pass value language), qa-tester (model, test case
format, evidence routing, ambiguous criteria, regression scope).

Specs updated: smoke-check and adopt specs rewritten to match actual skill
behavior. catalog.yaml reset to blank template state. Removed
session-state marketing research file, removed session-state from gitignore.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/skills/sprint-status/SKILL.md

@@ -78,6 +78,27 @@ Optionally (fast check only — do not do a deep scan): grep `src/` for a
 directory or file name that matches the story's system slug to check for
 implementation evidence. This is a hint only, not a definitive status.
 
+### Stale Story Detection
+
+After collecting status for all stories, check each IN PROGRESS story for staleness:
+
+- For each story that has a referenced file, read the file and look for a
+  `Last Updated:` field in the frontmatter or header (e.g., `Last Updated: 2026-04-01`
+  or `updated: 2026-04-01`). Accept any reasonable date field name: `Last Updated`,
+  `Updated`, `last-updated`, `updated_at`.
+- Calculate days since that date using today's date.
+- If the date is more than 2 days ago, flag the story as **STALE**.
+- If no date field is found in the story file, note "no timestamp — cannot check staleness."
+- If the story has no referenced file (inline task), note "inline task — cannot check staleness."
+
+STALE stories are included in the output table and collected into an "Attention Needed"
+section (see Phase 5 output format).
+
+**Stale story escalation**: If any IN PROGRESS story is flagged STALE, the burndown verdict
+is upgraded to at least **At Risk** — even if the completion percentage is within the normal
+On Track window. Record this escalation reason: "At Risk — [N] story(ies) with no progress in
+[N] days."
+
 ---
 
 ## 4. Burndown Assessment
@@ -118,6 +139,13 @@ Keep the total output to 30 lines or fewer. Use this format:
 | [title]              | Must Have  | BLOCKED     | [owner] | [brief reason] |
 | [title]              | Should Have| NOT STARTED | [owner] |                |
 
+### Attention Needed
+| Story / Task         | Status      | Last Updated   | Days Stale | Note           |
+|----------------------|-------------|----------------|------------|----------------|
+| [title]              | IN PROGRESS | [date or N/A]  | [N days]   | [STALE / no timestamp — cannot check staleness / inline task — cannot check staleness] |
+
+*(Omit this section entirely if no IN PROGRESS stories are stale or have timestamp concerns.)*
+
 ### Burndown: [On Track / At Risk / Behind]
 [1-2 sentences. If behind: which Must Haves are at risk. If on track: confirm
 and note any Should Haves the team could pull.]