docs(init): initialize OpenYield (1 phases)

---ci---
project: oy
phase: 0
milestone: v0.1
status: specify
decisions:
  - id: D-001
    decision: Autonomy level set to full
    rationale: Requested by user
    confidence: 1.0
    alternatives: [supervised, guided]
---/ci---

Specification: Create a multiproject called OpenYield (OY) where each subsystem is an individual project.
Requirements: Create Gitea group oy at git.cloudinit.dev; subsystems in individual repos.
Constraints: CIAgent workflow, multi-project mode.
Out of scope: Subsystem implementation.

.ciagent/config.json

@@ -0,0 +1,22 @@
+{
+  "projects": [
+    {
+      "slug": "oy",
+      "name": "OpenYield"
+    }
+  ],
+  "active_project": "oy",
+  "autonomy": {
+    "level": "full",
+    "escalation_hooks": ["deploy", "delete_data", "merge_to_main"],
+    "decision_confidence_threshold": 0.6,
+    "max_revision_iterations": 3,
+    "clarify_budget": 10
+  },
+  "release": {
+    "forge": "gitea",
+    "base_url": "git.cloudinit.dev",
+    "owner": "oy",
+    "repo": "openyield"
+  }
+}