feat: rebrand to R&D-lab + WBD palette + lab-slide cards

Identity refresh aligned to Waterschap Brabantse Delta.

Brand
- HELIX → R&D-lab everywhere user-facing (SITE.name; literal "HELIX"s
  swept across routes, app.html, login, error messages, seed).
- New tagline: "Projects, innovations, and every strand between."
- Site description updated.

Palette (sourced from the official WSBD-logo.svg)
- Primary #0d4f9e, secondary #1fa0db, accent #bed137 — added as
  --wbd-blue / --wbd-cyan / --wbd-lime CSS vars and as wbd.* in
  tailwind.config.js. helix.* aliases now point to the WBD palette.
- Strand A (Projects) → #1fa0db cyan. Strand B (Innovations) → #bed137 lime.
- Body vignette + scroll-bar + legend dots repainted accordingly.

Composite logo
- New 24px nav glyph + favicon.svg: WBD-style tilted-square mark in WBD
  blues at the centre, helix strands (lime + cyan) wrapping it, lime
  "active site" dot at the crossing. Says "R&D-lab × Brabantse Delta"
  in one mark.

Lab-slide cards (VerticalHelix)
- Frosted-glass surface (backdrop-filter blur+saturate).
- Thick 5px strand-coloured stripe on the helix-facing edge (gradient,
  glowing shadow). Slide rounds the stripe corners; the rest is square.
- Slide header has the strand badge and a monospace serial number
  (01/03 etc) — lab-specimen feel.
- Dashed footer rule + "Open detail →" CTA.
- Inline link chips (Gitea / Dashboard / Demo / Docs / Paper / Video)
  with inline SVG icons + short labels. Hover lights up in the strand
  colour. Capped at 5 visible, "+N" overflow indicator.
- Real <a> chips inside the card without nested <a>: overlay-link
  pattern (transparent slide-link absolute fills the card, chips sit on
  z-index: 2 above it).

Server load
- + Page now fetches each project's links in one Drizzle relational
  query (db.query.projects.findMany with: { links }), capped at 12.
- + Form: strand picker (Project / Innovation radios) reads + persists
  the new column.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/seed.js

@@ -42,13 +42,13 @@ const projects = [
   {
     id: 'prj_helix',
     slug: 'helix',
-    title: 'HELIX',
+    title: 'R&D-lab',
     summary:
-      'This very site — the R&D showcase platform. EVOLV and every R&D strand, one helix.',
+      'This very site — the R&D lab of Waterschap Brabantse Delta. Projects, innovations, and every strand between.',
     body_md: [
-      '# HELIX',
+      '# R&D-lab',
       '',
-      'HELIX is the R&D showcase platform of Waterschap Brabantse Delta. It collects projects, innovations, and updates from across the team in one place — with deep links to the actual repos, dashboards, and demos.',
+      'The R&D-lab is the showcase platform of Waterschap Brabantse Delta. It collects projects, innovations, and updates from across the team in one place — with deep links to the actual repos, dashboards, and demos.',
       '',
       '## Stack',
       '',
@@ -60,7 +60,7 @@ const projects = [
       '',
       '## Why?',
       '',
-      'Innovations were scattered: Gitea repos here, Grafana dashboards there, slide decks elsewhere. HELIX is the strand they share.'
+      'Innovations were scattered: Gitea repos here, Grafana dashboards there, slide decks elsewhere. R&D-lab is the strand they share.'
     ].join('\n'),
     cover_url: null,
     strand: 'A',
@@ -117,13 +117,13 @@ const links = [
 const posts = [
   {
     id: 'pst_welcome',
-    slug: 'welcome-to-helix',
-    title: 'Welcome to HELIX',
+    slug: 'welcome-to-rd-lab',
+    title: 'Welcome to R&D-lab',
     summary: 'Why this site exists and how to contribute.',
     body_md: [
-      '# Welcome to HELIX',
+      '# Welcome to R&D-lab',
       '',
-      'HELIX is the home of R&D output at Waterschap Brabantse Delta. If you have a project, a dashboard, or a one-off experiment worth showing — it belongs here.',
+      'R&D-lab is the home of R&D output at Waterschap Brabantse Delta. If you have a project, a dashboard, or a one-off experiment worth showing — it belongs here.',
       '',
       '## How to post',
       '',