fix(session-ui): keep permission actions inside the dock prompt shell

[CannonRS]

Issue for this PR

Closes #48532

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Adds an opt-in footerInside prop to DockPrompt so permission actions can live inside the dock shell instead of a detached bottom tray, and tightens the permission footer layout for narrow widths.

DockPrompt renders the footer in a separate DockTray below the shell. On narrow composer widths the permission buttons overflow and the footer looks detached from the content. The new footerInside prop keeps the actions inside the shell, wrapped and right-aligned; the default behaviour (footer in the tray) is unchanged, so question docks are not affected. SessionPermissionDock opts in via footerInside, and the storybook story documents the permission variant.

How did you verify your code works?

• bun typecheck (tsgo) passes in packages/app and packages/session-ui.
• Manual observation of the permission dock at narrow composer widths, with the footer wrapped inside the shell; question docks render unchanged (footer stays in the tray).
• git diff --check clean; no unrelated changes.

Screenshots / recordings

n/a — will add a Storybook screenshot if a maintainer requests one.

Fork

• Source fork: https://github.com/mQorva/OpenCode
• Diff against this fork's dev: mQorva/OpenCode@dev...permission-dock-layout
• mQorva issue / context: n/a

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR