docs(messenger): add the per-app keybinding alphabet to the unification spec

I added a "Global Prefix Keybinding Alphabet" section to the messenger-unification spec. The per-app C-; prefix is a third keybinding surface, separate from the in-buffer chords (C-c C-c / C-c C-k / C-c C-a) and decision 6's cross-app verbs. Today the action leaf under each app is ad hoc: the same key means different things in Slack, Signal, Telega, and ERC. The section spells out the canonical actions, shows the inconsistency as a matrix, and proposes one leaf alphabet across all four, with the core seven verbs as the unifiable floor and the richer verbs as optional per-backend extensions.

I also added a smoke-first parity note to Phase 1 (build the controllable signel replacement to the capability floor, not its ceiling) and promoted the todo task to [#A] "Unify Signel and All Messengers into one UX" with a direct link to the spec.

1 files changed, 3 insertions, 3 deletions

diff --git a/todo.org b/todo.org
index 38b2188bb..150d23390 100644
--- a/todo.org
+++ b/todo.org
@@ -1033,11 +1033,11 @@ Spec: [[id:540bf06b-16b8-46c6-b459-c40d1b9c795d][keybinding-console-safety-spec-
 ** TODO [#B] ledger-config is orphaned — ledger-mode never configured :bug:quick:
 Nothing requires =modules/ledger-config.el= (verified by grep), so .dat/.ledger/.journal open without ledger-mode, reports, or flycheck-ledger. The module looks finished, not staged (unlike duet-config, which documents its pre-alpha orphaning). Decide: wire into init.el (+ =cj/executable-find-or-warn= for the ledger binary) or delete. From the 2026-06 config audit.
 
-** TODO [#B] Messenger window/key unification :feature:
+** TODO [#A] Unify Signel and All Messengers into one UX :feature:
 :PROPERTIES:
-:LAST_REVIEWED: 2026-06-13
+:LAST_REVIEWED: 2026-06-16
 :END:
-Spec: [[id:4bfc2011-8ffc-4765-8886-91df12141171][messenger-unification-spec.org]] (Draft, 2026-06-11). One library (=cj-messenger-lib.el=) gives every messenger the same shape: chat windows rise from the bottom (the signel rule, generalized), C-c C-c confirms, C-c C-k cancels, C-c C-a attaches — dispatched per backend through a registry + minor mode. Signel already conforms (reference backend); telega and slack join in phases 2-3; ERC later. All eight decisions settled 2026-06-11 (cancel closes an idle window; telega's filter-cancel shadow accepted; slack rooms join the bottom rule). Spec held open — Craig has more ideas to fold in before it's marked Ready.
+Spec: [[file:docs/specs/messenger-unification-spec.org][messenger-unification-spec.org]] ([[id:4bfc2011-8ffc-4765-8886-91df12141171][by id]], Draft, 2026-06-11; keybinding-alphabet section + smoke-first parity added 2026-06-16). One library (=cj-messenger-lib.el=) gives every messenger the same shape: chat windows rise from the bottom (the signel rule, generalized), C-c C-c confirms, C-c C-k cancels, C-c C-a attaches — dispatched per backend through a registry + minor mode. Signel already conforms (reference backend); telega and slack join in phases 2-3; ERC later. All eight decisions settled 2026-06-11 (cancel closes an idle window; telega's filter-cancel shadow accepted; slack rooms join the bottom rule). Spec held open — Craig has more ideas to fold in before it's marked Ready.
 
 ** PROJECT [#B] Migrate All Terminals From Vterm to Ghostel
 :PROPERTIES: