Telling the crew from the toolbar carries the page you were on #4091

Today the toolbar's tell form sends from with an empty page address, so the crew does not learn which page prompted the tell.

Done:

• [ ] The tell form on toolbarPage passes the page address (pageAddress, already validated and capped) and the environment, and the tell that lands names them ('from the preview of pull #N at /path').
• [ ] An over-long or off-origin address is cut or dropped at the boundary as pageAddress already does; the text is escaped where shown.
• [ ] Tests: a tell from a preview page records the pull and path; one from production records the path; bun x tsc --noEmit passes.

Files: src/web/studio/toolbar.ts, the tell action, a test. Risk: same function as the other toolbar issues; rebase onto whichever lands first.

Builder note: the pill's own tell link already carries the page (tellLink in src/apps/crew.ts, test/apps-toolbar-tell.test.ts). This issue is only the form on the toolbar page, which sends an empty address. Reuse tellLink's shape; don't add a second one.