WIP move tool calling to boxel message events and add support for multiple tool calls/commands

[lukemelia]

• add host tests for multiple tool calls
• add aibot tests for multiple tool calls with results
• Ensure code TODOs are addressed

[github-actions]

Host Test Results

    1 files  ±0      1 suites  ±0   22m 36s ⏱️ -50s
764 tests +1  762 ✔️ +3  2 💤  - 1  0 ❌ ±0 
769 runs  +1  767 ✔️ +4  2 💤  - 1  0 ❌  - 1 

Results for commit 899da9b. ± Comparison against base commit 40442c9.

This pull request removes 6 and adds 7 tests. Note that renamed tests count towards both.

Chrome 133.0 ‑ Spec preview: have ability to create new spec instances
Chrome 133.0 ‑ Spec preview: title does not default to "default"
Chrome 133.0 ‑ Spec preview: view when there are multiple spec instances
Chrome 133.0 ‑ Spec preview: view when there are no spec instances
Chrome 133.0 ‑ Spec preview: view when there is a single spec instance
Chrome 133.0 ‑ Spec preview: view when users cannot write

Chrome 133.0 ‑ Acceptance | Spec preview: have ability to create new spec instances
Chrome 133.0 ‑ Acceptance | Spec preview: title does not default to "default"
Chrome 133.0 ‑ Acceptance | Spec preview: view when there are multiple spec instances
Chrome 133.0 ‑ Acceptance | Spec preview: view when there are no spec instances
Chrome 133.0 ‑ Acceptance | Spec preview: view when there is a single spec instance
Chrome 133.0 ‑ Acceptance | Spec preview: view when users cannot write
Chrome 133.0 ‑ Acceptance | code-submode | playground panel: can choose another instance to be opened in playground panel

♻️ This comment has been updated with latest results.