Release 0.18.0

Consolidated integration release (!309) — 8 MRs:
- !280 deterministic attribution guard for false-P0 queue items (#120671)
- !257 personal-concerns workspace refresh + soft personal token budget
- !282 bg-task ready-work re-insertion (migration 014)
- !281 GHMEM dashboard rebrand + accurate KPI relabels
- !81/!82 per-memory visibility schema + caller-identity enforcement (#132/#133, migration 015)
- !231 import Claude Code native memory at setup (#224)
- !233 timeout work-review + guarded auto-resume for execute_directive (#119123)

Plus (merged separately, included in this release line):
- !293 deep_review opencode-resolution contract + diagnosable fallback
- !294 canonicalize queue entity refs (migration 013)
- observability: per-model token pricing, rolling-30d avg, business-time queue ages, daily-spend chart fix

Migration chain: 012 model_mix / 013 canonicalize / 014 ready_boost / 015 memory_visibility (SCHEMA_VERSION 15).