feat(mobile): thread chips show the thread's project icon#22243

fix(mobile): a chip icon capture that throws settles instead of crashing

fix(mobile): each chip icon tile is captured once

feat(mobile): thread chips show monogram and emoji project icons

feat(mobile): thread chips show the thread's project icon

fix(mobile): chat chips cover thread links only

fix(mobile): PR chips never hide an agent's link text

fix(mobile): PR chip state compares sync times as instants

fix(mobile): PR chips ignore pull requests unlinked from a stack

fix(mobile): thread links and PR URLs in chat render as chips