Phase 2: Suggest configuration system (.semfora/suggest.yaml)

[Kadajett]

Context

Part of the --suggest recommendations engine (see #135). Depends on #137, #138.

What to Build

1. src/suggest/config.rs — SuggestConfig

Load configuration from .semfora/suggest.yaml (fall back to defaults if absent):

pub struct SuggestConfig {
    pub rules: HashMap<String, RuleConfig>,    // per-rule enable/disable + thresholds
    pub groups: HashMap<String, bool>,          // group-level enable/disable
    pub confidence_threshold: f64,              // global minimum confidence (default: 0.0)
    pub scope: ScopeConfig,                     // include/exclude paths
    pub precommit: PrecommitConfig,             // pre-commit settings (used in Phase 4)
}

pub struct RuleConfig {
    pub enabled: bool,
    pub threshold: Option<f64>,  // rule-specific threshold override
}

pub struct ScopeConfig {
    pub include: Vec<String>,    // glob patterns
    pub exclude: Vec<String>,    // glob patterns
}

2. Config file format

.semfora/suggest.yaml:

rules:
  combine-functions: true
  dead-code: true
  complexity-reduction:
    enabled: true
    threshold: 15
  rename-for-discoverability: false

groups:
  naming: false

confidence_threshold: 0.7

scope:
  include: ["src/"]
  exclude: ["src/generated/", "vendor/"]

3. Integration

• SuggestEngine::new() loads config from .semfora/suggest.yaml if present
• Rules check config.rules[name].enabled and config.groups[group] before evaluating
• Scope filtering: skip symbols outside scope.include / inside scope.exclude
• semfora config suggest --init generates a default config file

4. CLI overrides

• --suggest-confidence 0.8 to override confidence threshold from CLI
• --suggest-group duplicates to run only one group

Acceptance Criteria

• Config loads from .semfora/suggest.yaml with serde
• Missing config file = all defaults (everything enabled, threshold 0.0)
• Individual rule enable/disable works
• Group enable/disable works
• Confidence threshold filtering works
• Scope include/exclude filters symbols correctly
• semfora config suggest --init creates default config
• Unit tests for config parsing, including partial configs

References

• Architecture: Research: Recommendations Engine Architecture (--suggest system) #135
• Existing config pattern: src/config.rs