#3651 feat(trace): review feature table and add e2e checks for Claude Code gaps

Continues spec issue-3635 (#3635): the feature table review (milestone 1, R-001) and more checks for the Claude Code column (milestone 2).

Feature table review (R-001, D-012):

• New "Setup" section with rows for hook installation and deletion, the trace run wrapper, and more than one agent in one repository.
• New rows for a missed session start, and for the role, title, and description of a spec source.
• The new cells are "Unknown". The suite found the Claude Code value of the spec source header row, so that cell is now "Yes".
• The appendix candidate "local storage welcome message" gets no row: the "Welcome message" row already covers local mode, and its check tests it.

New end-to-end checks for Claude Code:

• Subagents: a scenario where the agent starts a subagent. The evidence must hold the subagent and its token usage.
• Spec source pointers: the full read of the ticket file in the transcript must be a pointer to the spec material.
• Spec source role, title, and description: the ticket capture must hold all three.
• Shell commands in another checkout: the agent clones the remote and commits and pushes in the clone. The session must be recorded in the clone, and the file must be attributed to the AI. A scenario can now name the checkout where the agent pushes.

The feature filters of a manual run (CHAINLOOP_E2E_FEATURE and the others) are now separated by ;, because feature names can hold commas.

AI disclosure: Claude Code helped to write this change.