The previous lock implementation was advisory only — the relay's lock
table PK was (bucket_uid, card_uid, holder_id), so multiple users could
"hold" the same card simultaneously and the plugin only used the locks
to draw a small badge. Concurrent writers raced through LWW, and an
unsaved editor on User A could be silently overwritten when User B
saved (the symptom: cards appearing to "disappear" from User A's view
once their version was clobbered by an LWW pull).
Now an exclusive, server-enforced lock:
* relay schema: collab_card_locks PK is (bucket_uid, card_uid). One
lock per card. Migration drops the old 3-column-PK table on the
next bootstrap (locks are 60s ephemeral, no data to preserve).
* /api/collab-locks POST: returns 409 + holder info when another
tenant already holds it. Same holder refreshes the TTL.
* /api/collab-cards POST/DELETE: refuse with 423 + locked_by when a
foreign tenant holds the lock. The plugin's local edit is preserved
— the push just stays queued and retries on the next poll until
the lock expires or is released. Tombstones are gated the same way
so a card can't be deleted under the holder's editor.
* Plugin push phase: tracks blocked count + holder names, surfaces
them in the poll response so the frontend can toast the user.
Frontend lock-on-first-keystroke flow:
* The lock is no longer acquired on editor-open — opening for read
doesn't lock anything. On the FIRST input event in #inp-title or
#editor-body the plugin tries to acquire. On success, heartbeat
every 30 s; on 409, immediately enter editor takeover.
* Takeover mode: title + body inputs disabled, all three save
buttons get a capture-phase click blocker (stopImmediatePropagation
to defeat the editor's own listener), a window-level capture-phase
keydown blocker swallows Ctrl/Cmd+S (app.js binds save directly to
the shortcut, bypassing the buttons), and a banner inside the
modal explains the situation. The user can still copy their
unsaved text out before closing.
* If a foreign lock arrives via the regular poll while the editor is
already open on that card, the same takeover engages mid-session.
* Opening the editor on a card whose lock is *already* known to be
foreign starts in takeover mode without arming the input listeners
at all.
* Self-detection: poll response now carries `self` (the relay
username), cached as window._collabSelf, so we don't take ourselves
over and the board decoration ignores our own lock.
Visual:
* Board cards held by a foreign lock now get a frosted overlay +
centered lock icon + holder name (replaces the small corner badge).
* Editor takeover banner uses the danger accent. Save buttons get a
.collab-save-blocked dim style.
* New `.collab-lock-toast` variant of the existing conflict toast,
used for both "your push is queued because X is editing" and
"this card just got locked by X" notifications.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
thandClaude Opus 4.6
f6cf7b4358