refactor(lex): drop background tile, home stays resident + chain-form window
Third in the consolidation series. Lex had 3 tile entries: background
(lazy), home (window), chain-form (window). The lex-specific internal
pubsub was lex:session-changed, lex:recent-lexicons-changed, and
lex:open-create.
Option B chosen (two tiles remain, not one): chain-form is a
short-lived modal opened by cmd panel infrastructure via the
chain-popup:content / chain-popup:result channels owned by
app/cmd/panel.js. That wire cannot be inlined. Home is the long-lived
owner of state and commands (now resident:true), chain-form stays
ephemeral.
Changes:
- manifest.json: background tile removed, home marked resident:true,
lex:session-changed removed from pubsub topics.
- home.js: added noun-registration block (discoverCollections,
getAllNsids, registerLexNoun), removed lex:session-changed
publishes from saveSession and clearSession, replaced
DOMContentLoaded bootstrap with an async IIFE that calls
api.initialize, registers the noun, then runs UI init.
- background.js and background.html left on disk.
Preserved topics: lex:recent-lexicons-changed (home to chain-form,
still cross-window), lex:open-create (cmd palette to home),
chain-popup:content / chain-popup:result (cmd panel infra).