v2.0.0b6

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Event provenance: NULL target pid when the target is the actor itself

The pid payload added in d43f82e was documented as "NULL when the target is
the actor itself", but record_process_event always copied proc.id, so a
purely local VirtualAlloc or CreateThread looked identical to a cross-process
operation. Null the payload centrally in record_process_event when the target
process matches the actor's pos.pid, so a populated pid always means the
operation crossed a process boundary. Thread events keep tid, which is real
data (the created thread) even for a local create.

- profiler.py: pid payload is None when proc.id == pos.pid.
- profiler_events.py: ThreadInjectEvent.pid documents the NULL case, matching
  the other process-scoped events.
- doc/reporting.md: event examples show the actor in pos with the target as a
  pid payload, including the local (omitted pid) cases; report_version in the
  examples refreshed to 4.0.0.
- tests: local vs cross-process pid payloads for mem_alloc, thread_create,
  and thread_inject.

get_json_report uses exclude_none, so a local operation omits the pid key
entirely rather than emitting an explicit null.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Merge pull request #288 from mandiant/release/v2.0.0b3

Release v2.0.0b3

Merge pull request #286 from mandiant/worktree-fix-mutable-defaults

Fix mutable default arguments across codebase

Merge pull request #263 from mandiant/wb-unicorn2