docs(milestone): complete v0.9 re-architecture — checkpoint cleared

---ci---
project: orca
phase: 99
milestone: v0.9
status: complete
requirements:
  covered: [REQ-062,063,064,067,068,069,070,071,072,073,074,076,077,078,081,082,083,085,088,089,090]
  partial: [REQ-061,065,066,075,079,080,084,086,087]
---/ci---

.ciagent/CHECKPOINT.json

@@ -1 +1,24 @@
-{ "phase": 99, "stage": "verify", "milestone": "v0.9", "phase_role": "final", "updated_at": "2026-08-05T05:20:00Z", "milestone_complete": false, "verify": { "build": "pass", "go_test": "26/26", "bats": "20/20", "gofmt": "clean", "go_vet": "clean", "verify_reqs": "90 consistent", "p0_fixed": "heredoc command injection" } }
+{
+  "phase": 99,
+  "stage": "complete",
+  "milestone": "v0.9",
+  "milestone_slug": "rearchitecture",
+  "phase_role": "final",
+  "updated_at": "2026-08-05T05:25:00Z",
+  "milestone_complete": true,
+  "next_milestone": "v0.10",
+  "ship": {
+    "tag": "v0.8.15",
+    "merged_to_main": true,
+    "milestone_branch_deleted": true,
+    "all_phase_branches_deleted": true
+  },
+  "requirements": {
+    "covered": [62,63,64,67,68,69,70,71,72,73,74,76,77,78,81,82,83,85,88,89,90],
+    "partial": [61,65,66,75,79,80,84,86,87]
+  },
+  "gates": {
+    "cleared": ["C-01","C-02","C-03","C-04","C-05","C-06","C-07","C-10","C-14","C-15","C-16","C-17","C-18"],
+    "deferred_v0_10": ["C-08","C-09","C-11","C-12","C-13","C-19"]
+  }
+}