Adopt 2026-09-21 upstream batches: middle truncate, composer controls, and device tool updates #704

Tracking adoption of remaining upstream commits up to 61b25b88d7:

• f7efb5354a (#12805) feat(web): truncate branch names and paths in the middle
• a9ab9049bb (#12833) feat(web): show the pull request refresh spinning in the detail header
• a4bc7deb99 (#12836) fix(web): dismiss composer suggestions with Escape (Lexical adaptation)
• a6cb1dd205 (#12623) fix(mobile): keep the source worktree when starting a thread on a branch
• 6cc7f7006e (#12837) fix(web): keep composer controls visible while they fit
• 5c5fa5ffb6 (#12816) feat(devices): show installed and running tool versions per host
• 3b836f9942 (#12817) feat(devices): show automatic update progress and host retry
• 61b25b88d7 (#12818) feat(devices): add read-only update discovery and remote ownership

Note: dca84efb53 excluded as Tiptap-specific (Pylon uses Lexical).