The palette's "Tell the crew" opens a composer in place on any repository page and sends the page with the tell #1464

Part of #1059. Pull #1357 went red on "web ui > the composer, the verdicts and the settings sections carry their keys", because it changed the composer's markup that this test reads.

Done looks like

• [ ] On a file, a diff, a run, an issue, a pull or a look, the palette key, then "Tell the crew", opens a composer in place. One line, and Enter sends the tell with from set to the current path. The page does not navigate and nothing shifts.
• [ ] The existing composer keeps every key test/web-ui.test.ts reads. A new composer reuses the same markup instead of forking it.
• [ ] It works without JavaScript too: a plain link to the composer page, carrying from.
• [ ] Tests cover the composer markup on two kinds of page, and the tell's from round-trip.
• [ ] Every new test/*.test.ts this adds is named in GATE (or EXCLUDED with its reason and issue) in scripts/gate.ts in the same commit, and bun test test/check-list.test.ts passes before the push.
• [ ] Before pushing, run bun x tsc --noEmit and the test files this touches (the sandbox sets FORGE_TEST_SOCKET, so the server suites run there), and quote both results in the pull.

Files: src/web/palette.ts, src/web/chrome.ts, src/web/studio/*, test/web-ui.test.ts. Risk: the 25-minute check for any pull that touches src/web, until #1279 lands. Shell JS weight: keep the addition small. Builder: scout.