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

.agent/skills/wds-1-project-brief/templates/project-brief-dialog/USAGE.md

@@ -0,0 +1,81 @@
+# Dialog Template Usage
+
+## Quick Start
+
+**Copy to project:**
+```bash
+cp -r workflows/wds-1-project-brief/templates/project-brief-dialog projects/{{slug}}/dialog
+```
+
+**Update as you progress:**
+- Complete each file when the corresponding PB step finishes
+- Update README.md progress tracker
+- Append to decisions.md whenever key decisions are made
+
+---
+
+## What to Capture
+
+### DO:
+- Key questions + user responses (not full transcript)
+- Signal-based follow-ups that revealed insights
+- Reflection checkpoint (synthesis + confirmation + corrections)
+- Final outputs (vision, positioning, etc.)
+- WHY decisions were made
+
+### DON'T:
+- Verbatim transcripts
+- Procedural agent actions
+- Implementation details
+- Repetitive exchanges
+
+---
+
+## Mandatory Checkpoints
+
+**Document EVERY reflection:**
+1. Agent's synthesis (2-3 sentences)
+2. User confirmed or corrected?
+3. What was misunderstood? (if corrected)
+
+---
+
+## Integration with Steps
+
+**Each step file should mandate:**
+
+```markdown
+## Design Log Update
+
+Before marking complete:
+1. Update `dialog/{{step}}-{{name}}.md`
+2. Document reflection checkpoint
+3. Record final synthesis
+4. Mark complete in `dialog/README.md`
+```
+
+---
+
+## File Sizes
+
+All dialog files: 65-86 lines (well under 100-line target)
+
+---
+
+## Design Log (Meta-Level)
+
+**For multi-session work**, agents should use the design log for state tracking and `_progress/agent-experiences/` for session insights.
+
+**Location:** `{{root_folder}}/_progress/00-design-log.md`
+
+**Update Protocol:**
+1. Complete current task
+2. Update design log with changes
+3. Show git diff to user
+4. Record session insights in `_progress/agent-experiences/` if needed
+
+---
+
+## Purpose
+
+Create transparent record of discovery conversations so future agents (and humans) understand WHY decisions were made, not just WHAT was decided. The design log provides this continuity across sessions.