fix(tui): remove shells from their location

[kitlangton]

What

Remove a running shell through the location that owns it, even when the TUI is currently displaying another project location.

This follows up on #39691, which made session shells visible across loaded locations but left shell removal scoped to the current location.

Before / After

Before

1. Start a shell in location A.
2. Open the same session while the TUI's current location is B.
3. The Shell composer tab finds the shell by session and displays it.
4. Killing the shell sends its ID to location B, where that shell does not exist, so the process keeps running.

After

1. Shell synchronization and live events retain each shell's owning LocationRef.
2. The Shell composer tab sends removal to the selected shell's location.
3. The process is removed regardless of the TUI's current location.

How

• packages/tui/src/context/data.tsx stores shell location provenance for API results and shell.created events.
• packages/tui/src/routes/session/composer/shell-tab.tsx removes the selected shell through that stored location.
• packages/tui/test/cli/tui/data.test.tsx loads one session's shells from two locations, triggers the composer kill command, and verifies the DELETE query uses the owning directory and workspace. It also covers live-event provenance.

Scope

This does not change shell creation, synchronization ownership, or the server shell API.

Testing

• cd packages/tui && bun run test (575 passed, 5 skipped)
• cd packages/tui && bun typecheck
• Pre-push hook: bun turbo typecheck --concurrency=3 (33 tasks passed)