yoloyolo/.planning/milestones/v1.2-phases/09-frequency-design-and-group-architecture/09-02-PLAN.md

---
phase: 09-frequency-design-and-group-architecture
plan: 02
type: execute
wave: 1
depends_on: []
files_modified:
  - config/config.go
  - config/config_test.go
autonomous: true
requirements:
  - FREQ-04

must_haves:
  truths:
    - "autoAssignFreq returns Hz values in [2500, 4000] range, not the old [1200, 2350]"
    - "Auto-assigned classes cannot collide with any built-in frequency (max built-in is 2449 Hz, auto-assign starts at 2500 Hz)"
    - "TestAutoFreqAssignment passes with the new range bounds"
    - "addAutoFreqEntries produces FreqConfig with empty Group (zero value) for user-defined classes"
  artifacts:
    - path: "config/config.go"
      provides: "Updated autoAssignFreq constants"
      contains: "baseHz   = 2500.0"
    - path: "config/config_test.go"
      provides: "Updated range assertion"
      contains: "cfg.BaseHz < 2500.0 || cfg.BaseHz > 4000.0"
  key_links:
    - from: "config/config.go"
      to: "synth/config.go"
      via: "addAutoFreqEntries creates synth.FreqConfig entries"
      pattern: "synth\\.FreqConfig"
---

<objective>
Update the auto-assign frequency range from [1200, 2350] to [2500, 4000] Hz so custom user-defined classes cannot collide with any built-in frequency. Update the corresponding test assertion.

Purpose: Per D-04, the auto-assign range must be pushed above all built-in frequencies (max 2449 Hz) to prevent collision. The 51 Hz buffer between 2449 and 2500 guarantees no overlap.

Output: Updated config/config.go constants, updated config/config_test.go assertion.
</objective>

<execution_context>
@$HOME/.claude/get-shit-done/workflows/execute-plan.md
@$HOME/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/phases/09-frequency-design-and-group-architecture/09-CONTEXT.md
@.planning/phases/09-frequency-design-and-group-architecture/09-RESEARCH.md

<interfaces>
<!-- From config/config.go — current autoAssignFreq function (lines 208-219) -->
```go
func autoAssignFreq(className string) float64 {
    h := fnv.New32a()
    h.Write([]byte(className))
    const (
        baseHz   = 1200.0
        stepHz   = 50.0
        numSteps = uint32(24)
    )
    return baseHz + float64(h.Sum32()%numSteps)*stepHz
}
```

<!-- From config/config.go — addAutoFreqEntries (lines 225-238) -->
```go
func addAutoFreqEntries(cfgs map[classify.TrafficClass]synth.FreqConfig, userRules []classify.Rule, autoClasses map[classify.TrafficClass]bool) {
    for _, rule := range userRules {
        if _, exists := cfgs[rule.Class]; !exists {
            baseHz := autoAssignFreq(string(rule.Class))
            cfgs[rule.Class] = synth.FreqConfig{
                BaseHz:       baseHz,
                WaveformType: synth.WaveformSine,
                Harmonics:    synth.WaveformPresetHarmonics(synth.WaveformSine, baseHz, synth.SampleRate),
                Pan:          0.0,
            }
            autoClasses[rule.Class] = true
        }
    }
}
```

<!-- From config/config_test.go — current range assertion (line 363) -->
```go
if cfg.BaseHz < 1200.0 || cfg.BaseHz > 2350.0 {
    t.Errorf("GameServer BaseHz: got %v, want in [1200, 2350]", cfg.BaseHz)
}
```
</interfaces>
</context>

<tasks>

<task type="auto">
  <name>Task 1: Update autoAssignFreq constants and comment</name>
  <files>config/config.go</files>
  <read_first>
    - config/config.go (lines 208-238: autoAssignFreq function and addAutoFreqEntries)
  </read_first>
  <action>
1. In the `autoAssignFreq` function (line 208-219), update three things:

   a. Change the function comment from `[1200, 2350]` to `[2500, 4000]`:
   ```go
   // autoAssignFreq computes a deterministic frequency in [2500, 4000] Hz for a class name
   ```

   b. Change the constants inside the function:
   ```go
   const (
       baseHz   = 2500.0
       stepHz   = 50.0
       numSteps = uint32(31) // [2500, 4000] Hz in 50 Hz steps
   )
   ```

   Verification: `2500.0 + float64(30)*50.0 = 4000.0`. With numSteps=31, the modulo produces values 0..30, yielding Hz values 2500, 2550, ..., 4000.

2. Do NOT modify `addAutoFreqEntries`. The Group field will be zero-value `""` for auto-assigned entries, which is correct — user-defined classes are not part of any built-in family. The struct literal in addAutoFreqEntries does not need a `Group:` field because Go zero-initializes missing named fields.
  </action>
  <verify>
    <automated>cd /home/dev/workspace/yoloyolo && go build ./config/...</automated>
  </verify>
  <acceptance_criteria>
    - config/config.go contains `baseHz   = 2500.0` (NOT 1200.0)
    - config/config.go contains `numSteps = uint32(31)` (NOT 24)
    - config/config.go contains `// autoAssignFreq computes a deterministic frequency in [2500, 4000] Hz`
    - config/config.go still contains `stepHz   = 50.0` (unchanged)
    - `go build ./config/...` exits 0
  </acceptance_criteria>
  <done>autoAssignFreq produces frequencies in [2500, 4000] Hz range with 31 steps of 50 Hz</done>
</task>

<task type="auto">
  <name>Task 2: Update config_test.go auto-assign range assertion</name>
  <files>config/config_test.go</files>
  <read_first>
    - config/config_test.go (search for `1200.0` and `2350.0` — the TestAutoFreqAssignment assertion around line 363)
  </read_first>
  <action>
1. In `TestAutoFreqAssignment` (around line 363), update the range assertion:

   Change from:
   ```go
   if cfg.BaseHz < 1200.0 || cfg.BaseHz > 2350.0 {
       t.Errorf("GameServer BaseHz: got %v, want in [1200, 2350]", cfg.BaseHz)
   }
   ```

   To:
   ```go
   if cfg.BaseHz < 2500.0 || cfg.BaseHz > 4000.0 {
       t.Errorf("GameServer BaseHz: got %v, want in [2500, 4000]", cfg.BaseHz)
   }
   ```

2. Also update the test comment at the top of TestAutoFreqAssignment (around line 344-346) from:
   ```
   // NO [sounds.GameServer] -> FreqCfgs contains "GameServer" entry with BaseHz in [1200, 2350]
   ```
   To:
   ```
   // NO [sounds.GameServer] -> FreqCfgs contains "GameServer" entry with BaseHz in [2500, 4000]
   ```

3. Check if `TestAutoFreqSkipsBuiltins` (around line 563) references `BaseHz == 175.0` for HTTPS. After Plan 01 rebalances HTTPS to 150.0, this test will need its expected value updated from `175.0` to `150.0`. Find the assertion and update it.

   Search for `175.0` in config_test.go and update to `150.0` wherever it references the built-in HTTPS BaseHz.
  </action>
  <verify>
    <automated>cd /home/dev/workspace/yoloyolo && go test ./config/... -v -count=1 -run "TestAutoFreq"</automated>
  </verify>
  <acceptance_criteria>
    - config/config_test.go contains `cfg.BaseHz < 2500.0 || cfg.BaseHz > 4000.0` (NOT 1200/2350)
    - config/config_test.go contains `want in [2500, 4000]` in the error message
    - config/config_test.go contains `BaseHz in [2500, 4000]` in the test comment
    - If HTTPS 175.0 was referenced, it is now 150.0
    - `go test ./config/... -run TestAutoFreqAssignment` exits 0
    - `go test ./config/... -run TestAutoFreqDeterministic` exits 0
    - `go test ./config/... -run TestAutoFreqSkipsBuiltins` exits 0
  </acceptance_criteria>
  <done>All auto-assign test assertions match new [2500, 4000] range; HTTPS built-in reference updated to 150.0 if applicable; all config tests pass</done>
</task>

</tasks>

<verification>
- `go build ./config/...` compiles without errors
- `go test ./config/... -v -run "TestAutoFreq"` passes all auto-freq tests
- `go test ./...` passes full suite (cross-package with synth changes from Plan 01)
</verification>

<success_criteria>
- autoAssignFreq base is 2500.0 Hz, not 1200.0 (FREQ-04)
- numSteps is 31, producing range [2500, 4000] with 50 Hz steps
- No collision possible between built-in frequencies (max 2449 Hz) and auto-assign (min 2500 Hz)
- All config tests pass with updated assertions
</success_criteria>

<output>
After completion, create `.planning/phases/09-frequency-design-and-group-architecture/09-02-SUMMARY.md`
</output>