feat: design system overhaul — sidebar, AI chats, settings, brainstorm, color cleanup

- Sidebar: dynamic brand-accent colors, brainstorm section restyled
- AI chat general: popup panel with expand/collapse, hides when contextual AI open
- AI chat contextual: tabs reordered (Actions first), X close button, height fix
- Settings: all tabs restyled, 6 new color presets (sage, terracotta, iron, etc.)
- Global color cleanup: emerald/orange hardcoded → brand-accent dynamic
- Brainstorm page: orange → brand-accent throughout
- PageEntry animation component added to key pages
- Floating AI button: bg-brand-accent instead of hardcoded black
- i18n: all 15 locales updated with new AI/billing keys
- Billing: freemium quota tracking, BYOK, stripe subscription scaffolding
- Admin: integrated into new design
- AGENTS.md + CLAUDE.md project rules added

.agents/skills/wds-1-project-brief/templates/project-brief-dialog/decisions.md

@@ -0,0 +1,85 @@
+# Key Decisions Log
+
+**Project:** {{project_name}}
+**Format:** Append-only decision log
+
+---
+
+## Decision 1: {{decision_topic}}
+
+**Date:** {{date}}
+**Step:** {{step_where_decided}}
+**Session:** {{session_number}}
+
+**Context:**
+{{what_prompted_this_decision}}
+
+**What was decided:**
+{{the_decision}}
+
+**Why:**
+{{rationale}}
+
+**Impact:**
+{{how_this_shapes_project}}
+
+**Alternatives considered:**
+- {{option_1}} — {{why_not}}
+- {{option_2}} — {{why_not}}
+
+**Documented in:** {{file_path}}
+
+---
+
+## Decision 2: {{decision_topic}}
+
+**Date:** {{date}}
+**Step:** {{step_where_decided}}
+**Session:** {{session_number}}
+
+**Context:**
+{{what_prompted_this_decision}}
+
+**What was decided:**
+{{the_decision}}
+
+**Why:**
+{{rationale}}
+
+**Impact:**
+{{how_this_shapes_project}}
+
+**Alternatives considered:**
+- {{option_1}} — {{why_not}}
+- {{option_2}} — {{why_not}}
+
+**Documented in:** {{file_path}}
+
+---
+
+## Decision 3: {{decision_topic}}
+
+**Date:** {{date}}
+**Step:** {{step_where_decided}}
+**Session:** {{session_number}}
+
+**Context:**
+{{what_prompted_this_decision}}
+
+**What was decided:**
+{{the_decision}}
+
+**Why:**
+{{rationale}}
+
+**Impact:**
+{{how_this_shapes_project}}
+
+**Alternatives considered:**
+- {{option_1}} — {{why_not}}
+
+**Documented in:** {{file_path}}
+
+---
+
+_Continue appending decisions as they're made throughout the Product Brief process._