docs(P00): plan v0.9 — reordered 13-phase v0.9 + 19-phase v1.0 plan with grill gates

Records the reordered phase plan (already committed to ROADMAP.md in the
specify stage). v0.9 = 13 phases (P00 deprecation/migration/test-infra
pre-phase + P0a1 path-resolver + P0a2 namespace-CRUD + P0b parser +
P0c schemas+emitter + P01-P10 workloads + P0X ship). v1.0 = 19 phases
(P00 cache + P01 metrics + P01.5 SPIFFE spike + P02 ACL + P03 secrets +
P04 backup + P05 drain + P06 history + P07 recovery + P08 integration +
P09 collector + P10 transactional + P11 lint + P12 verify + P13 ns +
P14a/b/c migration split + P15 README + P15.5 threat-model + P16 final).
All 19 grill binding conditions (C-01..C-19) adopted as phase gates.
Note: C-04 sizing must run before P00 execution; current count is 40
phases across v0.9+v1.0, which exceeds the 35-phase split threshold —
C-04 may require splitting into v0.9 + v0.10 + v1.0.

---ci---
project: orca
phase: 0
milestone: v0.9
status: plan
---/ci---

.ciagent/CHECKPOINT.json

@@ -1,11 +1,11 @@
 {
   "phase": 0,
-  "stage": "ideate",
+  "stage": "plan",
   "milestone": "v0.9",
   "milestone_slug": "rearchitecture",
   "phase_role": "pre_execution",
   "attempts": 0,
-  "updated_at": "2026-08-05T02:10:00Z",
+  "updated_at": "2026-08-05T02:15:00Z",
   "milestone_complete": false,
   "next_milestone": null
 }