Profile re-architect + Memory facts

What's new

Profile (4 tabs)

• Full re-architect of /app/profile: 4 tabs (Profile, Activity, AI, Settings) instead of one long list.
• Sticky tab nav under the header — stays visible when scrolling.
• "Timezone" field is now a select from ~22 IANA TZs (was a freeform input).
• "Username" shows placeholder "Not set" instead of literal @—.

AI Memory

• Confidence filter for trait facts: AI-extracted traits below 80% confidence are hidden (previously everything was shown, including false-positive "Hasn't completed tasks for weeks" at 75%).
• Inline editing for preference facts (✎ → ✓/✕, Enter/Escape).
• confidenceStars(): 60→1⭐, 90+→5⭐ as a visual indicator.

Achievements → "Milestones"

• The old 7/19 grid felt demotivating. Now showing only unlocked + "N more ahead — keep going" label.
• 4 tiers: bronze/silver/gold/diamond with a colored dot.

Fixed

• Pro mismatch in admin: dashboard and table counted differently (one with expiry, one without).
• Mood chips in insights rendered Journal.moodGood ×3 literally — i18n namespace mismatch.
• Goal cards invisible (var(--card) undefined) — added shadcn alias in globals.scss.
• DB connection accumulation in dev (43 idle connections after a few hours) — HMR-safe globalThis singleton for postgres-js client.