refactor: C-series cleanup and TODO documentation

- Delete install.sh.deprecated (dead code)
- Add TODO(DEV-031) for ghost update scanner-side prevention
- Add TODO(DEV-030) with specific missing service cycles
- ETHOS sweep: zero banned words, emojis, or fmt.Printf
- All tests pass, Linux builds clean

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/Refactor_C_Series.md

@@ -0,0 +1,49 @@
+# C-Series Cleanup Report
+
+**Date:** 2026-03-29
+**Branch:** culurien
+
+---
+
+## Task 1: Dead Code Removal
+
+| Check | Result |
+|-------|--------|
+| `.broken` / `.deprecated` / `.restored` files | `install.sh.deprecated` found and deleted |
+| Compiled test binaries | None found (cleaned in A-series refactor) |
+| Dead function bodies in service/windows.go | None — runAgent() is active code with B-2 parity |
+
+## Task 2: DEV-031 TODO Documentation
+
+- `scanner/windows_wua.go`: TODO(DEV-031) added above scan result return
+- `installer/windows.go`: TODO(DEV-031) added at RebootRequired flag
+
+## Task 3: DEV-030 TODO Documentation
+
+- `service/windows.go`: TODO(DEV-030) enhanced with specific missing cycles (ShouldRefreshKey, CleanupExecutedIDs) and pointer to docs
+
+## Task 4: ETHOS Sweep
+
+| Check | Files | Result |
+|-------|-------|--------|
+| Banned words | winget.go, windows.go, types.go | Zero matches |
+| Emojis | scanner/, installer/, service/ | Zero matches |
+| fmt.Printf | winget.go, installer/windows.go | Zero matches |
+
+## Task 5: Build & Test
+
+- All 4 agent test packages pass (scanner, internal, circuitbreaker, crypto)
+- All 6 server test packages pass
+- Pre-existing migration/pathutils build error is unchanged (not C-series related)
+
+## Files Deleted
+
+- `aggregator-agent/install.sh.deprecated`
+
+## Files Modified
+
+- `scanner/windows_wua.go` — TODO(DEV-031) added
+- `installer/windows.go` — TODO(DEV-031) added
+- `service/windows.go` — TODO(DEV-030) enhanced
+
+## Status: CLEAN