docs(M03): seed M03 plan and toolcalls

Made-with: Cursor

docs/milestones/M03/M03_plan.md

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+# M03 Plan — Test Architecture
+
+**Milestone:** M03  
+**Title:** Test architecture (smoke / quality / nightly)  
+**Status:** Not Started  
+**Depends on:** M02 (complete)
+
+---
+
+## Intent
+
+Introduce test tiers to improve signal clarity and prepare for higher coverage targets:
+
+- **Smoke** — Fast subset, required on PR
+- **Quality** — Full suite with coverage gate
+- **Nightly** — Heavier tests, optional/alert
+
+---
+
+## Scope
+
+(To be elaborated.)
+
+---
+
+## Definition of Done
+
+(To be elaborated.)

docs/milestones/M03/M03_toolcalls.md

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+# M03 Tool Calls
+
+Milestone: M03  
+Branch: (to be created)
+
+This file records Cursor tool calls performed during the milestone.
+
+| Timestamp | Tool | Purpose | Files/Target | Status |
+|-----------|------|---------|--------------|--------|