Add a workflow observatory over recorded thread events

[John-Ryan21337]

Adds a workflow observatory over the selected thread's recorded agent events. Open Workflow from the composer to inspect reported tasks in a list or graph, even when the thread has no plan. This independent adoption proposal targets current Cafe dev (99fbaec8) and is tracked in #90.

The view uses Cafe's existing event projection. It keeps repeated provider identifiers distinct across turns, bounds the output to 64 nodes and 100 recent activity rows, and shows missing fields as Not reported. Relationships and terminal states come from recorded events; age does not invent a completion or stopped state. The displayed observed span is the interval between recorded updates, not provider runtime. Closing or changing the selected thread or environment clears the view state.

This is a read-only renderer feature. It adds no provider launch behavior, event collector, task control or inferred agent-to-agent relationships. Recorded provider text can contain sensitive project information; the separate provider history binding is not copied into the snapshot or DOM.

Independent review checked fidelity, bounded projection, graph layout and selection cleanup. The delimiter-collision regression also verifies the existing explicit environment/thread reset; it is coverage, not a claim that the workflow panel previously leaked selection state.

Validation on Windows: yarn fmt, yarn lint, yarn typecheck (10/10), yarn test --concurrency=2 (10/10; server 2,004 passed and the inherited POSIX bootstrap FIFO skip), full Chromium 317/317, and yarn build:desktop --force (3/3). Generated server, desktop and renderer bundles were checked. Focused projection/layout 22/22 and component Chromium 11/11 passed. Existing platform-specific script skips are unchanged. No live provider or user account was tested.

Review media uses synthetic events and the real component stylesheet:

Interaction recording, 7.68 seconds

Scope and verification