feature: Bob support — detection, settings, parsed events, token and cost accounting

Feature Description

Bob support on the agent integration contract. Bob is our internal coding agent, and this is
an internal release: Bob is an agent our own team runs, so observability for it is much of
what the release is for.

Proposed Solution

• Confirm Bob's wire format and where it stores settings — unlike the other agents there is
  no public reference, so capture this in the issue before implementing
• Detect an installed Bob and locate its settings
• Patch it to use localhost:47600 and the Cortex CA; ask before editing, support revert
• Traffic parsed into typed events, not merely proxied
• Token counts and cost correct for its wire format
• Metrics aggregate alongside other agents
• A tool inventory, or state explicitly that tool pruning is unsupported
• Setup documented; verified depth stated

Additional Context

Part of the Cortex v0.9.0 release. Depends on the agent integration contract.