v2.0.5 — Read feature (mobile zen reader on the relay)

Per-card opt-in push to the relay for distraction-free mobile reading.
Not tag-based: a real cards.read_push column so the reading state
stays independent of whatever tags the user organises by.

hyprcrd
- cards.read_push column (0/1, default 0) via Database migration.
- POST /api/cards + PATCH /api/cards/{id} accept read_push; save hook
  posts the card (title+body, encrypted) and referenced images
  to the relay's /api/read endpoint. First inline image is flagged
  as the hero. Toggle-off / DELETE wipes the remote copy.
- Detail-bar toggle button ("Read" → "On relay") with filled book
  icon + inverted accent background when active; outline book icon
  in the bottom meta row of the board card when read_push=1.

relay
- read_items + read_attachments tables, encrypted under the
  inter-tenant key like messages (dual-format envelope).
- Client API: POST /api/read, DELETE /api/read/{uid}, POST
  /api/read-attachments. Session API: GET /api/read (list),
  GET /api/read/{uid} (single decrypted), GET /api/read-attachments/
  {uid}/{filename} (serves decrypted image bytes).
- Payload size caps raised to 15MB (attachments) / 2MB (items).
- New nav tab + view: list with thumbnails, click opens a zen reader
  overlay. Reader caps article width at 680px, bumps type to 17px/1.7,
  renders a minimal markdown subset (headings, lists, code fences,
  blockquotes, links, inline images), rewrites uploads/ references
  to the session-authed image endpoint. Escape closes the reader.
- Mobile-first: wider touch targets, tighter padding at ≤640px.

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

src/Database.php

@@ -124,6 +124,13 @@ class Database
         if (!in_array('relay_uid', $colNames)) {
             self::$pdo->exec('ALTER TABLE cards ADD COLUMN relay_uid TEXT DEFAULT NULL');
         }
+        // Read-later push: when 1, saves propagate the card to the relay's
+        // /api/read endpoint so the user can read it in the mobile-friendly
+        // zen reader. Explicitly NOT tag-based (so reading-mode is
+        // independent of whatever tags the user already organises by).
+        if (!in_array('read_push', $colNames)) {
+            self::$pdo->exec('ALTER TABLE cards ADD COLUMN read_push INTEGER NOT NULL DEFAULT 0');
+        }
 
         // Relay pushed message IDs (skip on own poll)
         self::$pdo->exec('