chore: my-deepagent-seed (BudgetTracker PoC + v0.1.0 seed assets)

Pre-flight assets prepared on the main machine before the new-machine
rewrite of my-deepagent in Python.

- poc/: BudgetTracker + CostMiddleware + MockChatModel PoC.
  Validates wrap_model_call pattern, SQLite WAL + ON CONFLICT upsert,
  per-scope cap accounting. 5/5 pytest PASS in isolated uv venv.
- schemas/: 10 personas (Anthropic Sonnet/Opus/Haiku + DeepSeek mix),
  3 workflows (spec-and-review, bug-fix-with-reproduction,
  code-investigation), 4 artifact JSON Schemas (dev/spec@1,
  dev/phase-plan@1, dev/review-finding-batch@1, common/final-report@1).
- schemas/validate.py: pydantic + Draft202012 cross-validation.
  18/18 assets verified.
- README.md: new-machine bootstrap instructions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

my-deepagent-seed/schemas/artifacts/dev/phase-plan@1.json

@@ -0,0 +1,80 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "dev/phase-plan@1",
+  "title": "Dev Phase Plan",
+  "description": "실행 단계 계획 (spec 기반 phase 분해)",
+  "type": "object",
+  "required": ["runId", "phaseKey", "phases"],
+  "additionalProperties": false,
+  "properties": {
+    "runId": {
+      "type": "string",
+      "format": "uuid",
+      "description": "실행 고유 식별자 (spec.json과 동일한 UUID)"
+    },
+    "phaseKey": {
+      "type": "string",
+      "minLength": 1,
+      "description": "현재 phase 키 (통상 planning)"
+    },
+    "phases": {
+      "type": "array",
+      "items": {
+        "type": "object",
+        "required": ["key", "title", "role", "instructions"],
+        "additionalProperties": false,
+        "properties": {
+          "key": {
+            "type": "string",
+            "pattern": "^[a-z][a-z0-9-]*$",
+            "description": "단계 고유 식별자 (영소문자, 하이픈 허용)"
+          },
+          "title": {
+            "type": "string",
+            "minLength": 1,
+            "description": "단계 제목"
+          },
+          "role": {
+            "type": "string",
+            "minLength": 1,
+            "description": "담당 역할 ID"
+          },
+          "instructions": {
+            "type": "string",
+            "minLength": 10,
+            "description": "담당자에 대한 구체적인 지시사항"
+          },
+          "expected_artifact": {
+            "type": "object",
+            "required": ["path", "schema"],
+            "additionalProperties": false,
+            "properties": {
+              "path": {
+                "type": "string",
+                "description": "산출물 파일 경로"
+              },
+              "schema": {
+                "type": "string",
+                "description": "산출물 JSON Schema ID"
+              }
+            },
+            "description": "이 단계에서 생성할 산출물 (선택)"
+          },
+          "depends_on": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            },
+            "description": "이 단계 실행 전에 완료돼야 할 선행 단계 키 목록 (선택)"
+          }
+        }
+      },
+      "description": "실행 단계 목록"
+    },
+    "estimated_duration_hours": {
+      "type": "number",
+      "minimum": 0,
+      "description": "전체 예상 소요 시간 (시간 단위, 선택)"
+    }
+  }
+}