Murali/concurrent edits

[muraalee]

Fix dropped edits from concurrent async hooks

When Claude Code edits multiple files in quick succession, the async
PostToolUse hooks spawn multiple capture processes simultaneously.
Without busy_timeout, concurrent SQLite writes would fail with
SQLITE_BUSY and edits would be silently dropped.

Changes:

• Add PRAGMA busy_timeout = 5000 to retry writes for up to 5 seconds
• Add debug logging (AGENTBLAME_DEBUG=1) to diagnose missing captures