[pull] main from microsoft:main - #1622

* Enhance ActivitybarPart: add floating action gap and improve composite size calculation

* activitybar: separate items with a dynamic gap in floating panels mode

* activitybar: adjust composite bar layout to correctly account for leading item gap

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* activitybar: cover the measured global activity icons reservation

The global bar height is measured from the DOM rather than derived from the
item size, but no test exercised it. Add coverage for one and two global
actions so the measured reservation, and the single gap that separates two
icons, cannot silently regress.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: mrleemurray <mrleemurray@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* sessions: gate opening a session on workspace trust

Opening a session from the sessions list (click or Alt-click open-to-the-side) now refuses when the session's mounted folder is not trusted, leaving the current session (or the empty new-session slot) untouched and offering a "Trust Folder" action. Worktrees VS Code creates off an already-trusted repo are auto-trusted so worktree sessions still open seamlessly, and the workspace folder is never mounted while untrusted so the window cannot silently enter Restricted Mode. Replaces the previous silent force-trust on session open.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* sessions: use the standard trust dialog when opening an untrusted session

Opening an untrusted session from the list now surfaces VS Code's standard workspace-trust request instead of a custom "Trust Folder" notification. Because the gate runs from the imperative open path (the list handler) rather than the reactive folder-mount code, the prompt fires once per open and cannot loop. Declining leaves the current session untouched; granting trust opens the session and is remembered for next time.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* sessions: check every session folder's trust when opening

The open-trust gate now verifies all of a session's working directories, not just the primary/mounted one. The agent and its tasks, terminals and other tooling can run against any working directory, so we make no assumptions that non-primary folders are harmless: a session only opens once every folder is trusted, prompting via the standard trust dialog for each untrusted one and refusing the open if the user declines any.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* sessions: test the open-trust gate and tighten its JSDoc

Adds regression tests for the sessions-list open gate: proves canOpenSession=false blocks both mark-read and onSessionOpen, and that both happen only after the gate resolves true, with a control test proving the click gesture actually reaches onDidOpen. Trims the canOpenSession JSDoc to the codebase's concise style and drops the sessions-list coupling. Addresses PR review feedback.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Fixes #331988

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

sessions: remove workspace chat pill

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Dmitriy Vasyura <dmitriv@microsoft.com>

build: log files left after Windows uninstall

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

A page the agent opened in a browser showed up twice: once as a browser
entry and once as a website artifact. The browsers control now publishes
the URLs it lists (empty while the user hides the pill), and the artifact
sections drop website artifacts pointing at one of those pages, matched
on a normalized key so origin casing and a trailing slash still match.

Website artifacts also open with contributed openers now, the same way
the link opens from the response markdown it came from, so a localhost
artifact lands in the integrated browser instead of the system one.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Dmitriy Vasyura <dmitriv@microsoft.com>

chat: adjust padding for progress row to maintain scroll anchoring

Co-authored-by: mrleemurray <mrleemurray@users.noreply.github.com>
Co-authored-by: Dmitriy Vasyura <dmitriv@microsoft.com>