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/retrospective/SKILL.md

@@ -14,6 +14,28 @@ Determine whether this is a sprint retrospective (`sprint-N`) or a milestone ret
 
 ---
 
+## Phase 1b: Check for Existing Retrospective
+
+Before loading any data, glob for an existing retrospective file:
+
+- For sprint retrospectives: `production/retrospectives/retro-[sprint-slug]-*.md`
+  (also check `production/sprints/sprint-[N]-retrospective.md` as an alternate location)
+- For milestone retrospectives: `production/retrospectives/retro-[milestone-name]-*.md`
+
+If a matching file is found, present the user with:
+
+```
+An existing retrospective was found: [filename]
+
+[A] Update existing retrospective — load it and add/revise sections
+[B] Start fresh — generate a new retrospective, archiving the old one
+```
+
+Wait for user selection before continuing. If updating, read the existing file and
+carry its content forward into the generation phase, revising sections with new data.
+
+---
+
 ## Phase 2: Load Sprint or Milestone Data
 
 Read the sprint or milestone plan from the appropriate location:
@@ -21,6 +43,20 @@ Read the sprint or milestone plan from the appropriate location:
 - Sprint plans: `production/sprints/`
 - Milestone definitions: `production/milestones/`
 
+**If the file does not exist or is empty**, output:
+
+> "No sprint data found for [sprint/milestone]. Run `/sprint-status` to generate
+> sprint data first, or provide the sprint details manually."
+
+Then use `AskUserQuestion` to present two options:
+
+- **[A] Provide data manually** — ask the user to paste or describe the sprint
+  tasks, dates, and outcomes; use that as the source of truth for the retrospective.
+- **[B] Stop** — abort the skill. Verdict: **BLOCKED** — no sprint data available.
+
+If the user chooses [A], collect the data and continue to Phase 3 using what they provide.
+If the user chooses [B], stop here.
+
 Extract: planned tasks, estimated effort, owners, and goals.
 
 Read the git log for the period covered by the sprint or milestone to understand what was actually committed and when.