docs(09-02): complete auto-assign range update plan

.planning/REQUIREMENTS.md

@@ -28,7 +28,7 @@ Requirements for extended protocol coverage milestone. Each maps to roadmap phas
 - [ ] **FREQ-01**: All traffic classes (existing + new) are redistributed into group-coherent frequency bands using musical interval ratios (not fixed Hz steps)
 - [ ] **FREQ-02**: Within-family protocols are separated by at least a major second interval (ratio 1.122) to avoid critical band masking
 - [ ] **FREQ-03**: The full frequency allocation table is designed and documented before any FreqConfig code is written
-- [ ] **FREQ-04**: Auto-assign frequency range for user custom classes is updated to avoid collision with new built-in frequencies
+- [x] **FREQ-04**: Auto-assign frequency range for user custom classes is updated to avoid collision with new built-in frequencies
 
 ### Group System
 
@@ -71,7 +71,7 @@ Which phases cover which requirements. Updated during roadmap creation.
 | FREQ-01 | Phase 9 | Pending |
 | FREQ-02 | Phase 9 | Pending |
 | FREQ-03 | Phase 9 | Pending |
-| FREQ-04 | Phase 9 | Pending |
+| FREQ-04 | Phase 9 | Complete |
 | GRP-01 | Phase 9 | Pending |
 | GRP-04 | Phase 9 | Pending |
 | PROTO-01 | Phase 10 | Pending |

.planning/ROADMAP.md

@@ -63,10 +63,10 @@ Plans:
   2. Every within-family pair of frequencies satisfies at least a major second interval (ratio 1.122), verifiable by inspection of the table
   3. The `autoAssignFreq` base for user-defined custom classes is set above all built-in frequencies, with no collision possible
   4. `FreqConfig` has a `Group` string field and all existing `ClassFreqConfigs` entries compile with the new struct shape
-**Plans:** 2 plans
+**Plans:** 1/2 plans executed
 Plans:
 - [ ] 09-01-PLAN.md — Add Group field to FreqConfig, rebalance ClassFreqConfigs to major-second ladder
-- [ ] 09-02-PLAN.md — Update auto-assign range from [1200,2350] to [2500,4000] Hz
+- [x] 09-02-PLAN.md — Update auto-assign range from [1200,2350] to [2500,4000] Hz
 
 ### Phase 10: Classification Layer
 **Goal**: All new protocol families are classified — ~21 new TrafficClass constants exist, AllClasses() covers them, and DefaultRules maps all new ports to their classes
@@ -102,6 +102,6 @@ Plans:
 | 6. Config Package and Sound Overrides | v1.1 | 2/2 | Complete | 2026-03-26 |
 | 7. Custom Rules and Print-Config | v1.1 | 2/2 | Complete | 2026-03-26 |
 | 8. Test and Constant Cleanup | v1.2 | 1/1 | Complete   | 2026-03-27 |
-| 9. Frequency Design and Group Architecture | v1.2 | 0/2 | Not started | - |
+| 9. Frequency Design and Group Architecture | v1.2 | 1/2 | In Progress|  |
 | 10. Classification Layer | v1.2 | 0/? | Not started | - |
 | 11. Synthesis and Config Layer | v1.2 | 0/? | Not started | - |

.planning/STATE.md

@@ -2,15 +2,15 @@
 gsd_state_version: 1.0
 milestone: v1.2
 milestone_name: Extended Protocol Coverage
-status: verifying
+status: executing
-stopped_at: Phase 9 context gathered
+stopped_at: Completed 09-02-PLAN.md (auto-assign range update)
-last_updated: "2026-03-27T12:45:39.811Z"
+last_updated: "2026-03-27T13:09:48.759Z"
 last_activity: 2026-03-27
 progress:
   total_phases: 4
   completed_phases: 1
-  total_plans: 1
+  total_plans: 3
-  completed_plans: 1
+  completed_plans: 2
   percent: 0
 ---
 
@@ -21,13 +21,13 @@ progress:
 See: .planning/PROJECT.md (updated 2026-03-27)
 
 **Core value:** Network traffic patterns are instantly recognizable as distinct sounds — a ping sounds different from HTTPS noise, which sounds different from a port scan.
-**Current focus:** Phase 08 — test-and-constant-cleanup
+**Current focus:** Phase 09 — frequency-design-and-group-architecture
 
 ## Current Position
 
-Phase: 9
+Phase: 09 (frequency-design-and-group-architecture) — EXECUTING
-Plan: Not started
+Plan: 2 of 2
-Status: Phase complete — ready for verification
+Status: Ready to execute
 Last activity: 2026-03-27
 
 Progress: [░░░░░░░░░░] 0%
@@ -50,6 +50,7 @@ Progress: [░░░░░░░░░░] 0%
 
 **Recent Trend:** Stable
 | Phase 08 P01 | 1 | 2 tasks | 2 files |
+| Phase 09 P02 | 3 | 2 tasks | 2 files |
 
 ## Accumulated Context
 
@@ -63,6 +64,7 @@ Progress: [░░░░░░░░░░] 0%
 - [Phase 07]: LoadResult struct chosen over tuple return for config.Load() — cleaner API contract
 - [Phase 08]: NumLayers and GainPerLayer deleted — dead code since NewBank computes gain dynamically as 1/N
 - [Phase 08]: TestFrequenciesInRange now validates against Nyquist (22050 Hz) — any new BaseHz in (0, 22050) is accepted without test surgery
+- [Phase 09]: autoAssignFreq range moved to [2500, 4000] Hz with numSteps=31 to guarantee no collision with built-in frequencies (max 2449 Hz)
 
 ### Pending Todos
 
@@ -75,6 +77,6 @@ Progress: [░░░░░░░░░░] 0%
 
 ## Session Continuity
 
-Last session: 2026-03-27T12:45:39.804Z
+Last session: 2026-03-27T13:09:48.752Z
-Stopped at: Phase 9 context gathered
+Stopped at: Completed 09-02-PLAN.md (auto-assign range update)
-Resume file: .planning/phases/09-frequency-design-and-group-architecture/09-CONTEXT.md
+Resume file: None

.planning/phases/09-frequency-design-and-group-architecture/09-02-SUMMARY.md

@@ -0,0 +1,78 @@
+---
+phase: 09-frequency-design-and-group-architecture
+plan: "02"
+subsystem: config
+tags: [frequency-design, auto-assign, collision-prevention, test-update]
+dependency_graph:
+  requires: []
+  provides: [updated-autoAssignFreq-range, collision-free-auto-assign]
+  affects: [config/config.go, config/config_test.go]
+tech_stack:
+  added: []
+  patterns: [FNV-32a hash, deterministic frequency assignment]
+key_files:
+  created: []
+  modified:
+    - config/config.go
+    - config/config_test.go
+decisions:
+  - "autoAssignFreq range moved to [2500, 4000] Hz with numSteps=31 (50 Hz steps) to guarantee 51 Hz gap above max built-in frequency of 2449 Hz"
+  - "TestAutoFreqSkipsBuiltins updated to expect 150.0 for HTTPS (coordinated with Plan 01 rebalancing)"
+metrics:
+  duration: "~3 min"
+  completed: "2026-03-27"
+  tasks_completed: 2
+  files_modified: 2
+---
+
+# Phase 9 Plan 2: Auto-Assign Frequency Range Update Summary
+
+Update autoAssignFreq to use [2500, 4000] Hz with 31 steps of 50 Hz, ensuring no collision with any built-in frequency (max 2449 Hz after Phase 9 Plan 1 rebalancing).
+
+## What Was Built
+
+Updated the `autoAssignFreq` function constants and corresponding test assertions so user-defined traffic classes are always assigned frequencies in the [2500, 4000] Hz range, safely above all built-in protocol frequencies.
+
+## Tasks Completed
+
+| Task | Name | Commit | Files |
+|------|------|--------|-------|
+| 1 | Update autoAssignFreq constants and comment | 8ae1ddc | config/config.go |
+| 2 | Update config_test.go auto-assign range assertion | dbcbeb3 | config/config_test.go |
+
+## Changes Made
+
+### Task 1: config/config.go
+
+- Changed `baseHz` constant from `1200.0` to `2500.0`
+- Changed `numSteps` from `uint32(24)` to `uint32(31)` (covers [2500, 4000] in 50 Hz steps: 2500 + 30*50 = 4000)
+- Updated function comment from `[1200, 2350]` to `[2500, 4000]`
+- `stepHz = 50.0` unchanged
+
+### Task 2: config/config_test.go
+
+- Updated `TestAutoFreqAssignment` comment from `[1200, 2350]` to `[2500, 4000]`
+- Updated range bounds assertion from `< 1200.0 || > 2350.0` to `< 2500.0 || > 4000.0`
+- Updated `TestAutoFreqSkipsBuiltins` HTTPS expected value from `175.0` to `150.0` (coordinated with Plan 01 HTTPS rebalancing)
+
+## Verification Results
+
+- `go build ./config/...` exits 0
+- `TestAutoFreqAssignment` passes
+- `TestAutoFreqDeterministic` passes
+- `TestAutoFreqSkipsBuiltins` will pass once Plan 01 updates HTTPS BaseHz to 150.0
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Known Stubs
+
+None.
+
+## Self-Check: PASSED
+
+- config/config.go contains `baseHz   = 2500.0`: FOUND
+- config/config.go contains `numSteps = uint32(31)`: FOUND
+- config/config_test.go contains `cfg.BaseHz < 2500.0 || cfg.BaseHz > 4000.0`: FOUND
+- Commits 8ae1ddc and dbcbeb3 exist in git log