chore(docs): clean up PAN-COMMANDS.md draft text and add dispatch tuning docs

[akougkas]

Problem

1. .specs/PAN-COMMANDS.md contains draft reasoning text at lines 45-58 ("Wait: /export, /share...", "Actually the code comment...") that was not cleaned up before writing.

2. Five dispatch tuning parameters (timeout, maxDepth, concurrency, heartbeatInterval, workerTimeout) are admin-only and have no slash commands. This is arguably correct for admin-only params, but /doctor cannot suggest parameter adjustments that the user can apply directly.

3. The CONFIG_CHANGED handler uses a switch/case on event.key with an empty default branch. Adding new config params to the schema does not produce a compile-time error if the handler is not updated.

4. The sharedBus uses string-typed channel names at runtime. BusEventMap provides type documentation but emit/on accept plain strings. A typo in a channel name creates a silent no-op.

Audit Reference

AUDIT-ISSUES.md: C9, E7, F4, F5

Objective

Clean up documentation and address minor architecture hygiene.

Deliverables

• Remove draft text from PAN-COMMANDS.md (lines 45-58)
• Add dispatch tuning reference to /doctor output (current values + how to change via tool)
• Add exhaustive key check comment or type guard to CONFIG_CHANGED handler
• Consider typed sharedBus wrapper with compile-time channel name validation (future enhancement)