fix: remove vestigial state.json files from agent directories

Agent directories (witness/, refinery/, mayor/) contained state.json files
with last_active timestamps that were never updated, making them stale and
misleading. This change removes:

- initAgentStates function that created vestigial state.json files
- AgentState type and related Load/Save functions from config package
- MayorStateValidCheck from doctor checks
- requesting_* lifecycle verification (dead code - flags were never set)
- FileStateJSON constant and MayorStatePath function

Kept intact:
- daemon/state.json (actively used for daemon runtime state)
- crew/<name>/state.json (operational CrewWorker metadata)
- Agent state tracking via beads (the ZFC-compliant approach)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/config/types.go

@@ -65,14 +65,6 @@ type BeadsConfig struct {
 	Prefix string `json:"prefix"` // issue prefix
 }
 
-// AgentState represents an agent's current state (*/state.json).
-type AgentState struct {
-	Role       string         `json:"role"`              // "mayor", "witness", etc.
-	LastActive time.Time      `json:"last_active"`
-	Session    string         `json:"session,omitempty"`
-	Extra      map[string]any `json:"extra,omitempty"`
-}
-
 // CurrentTownVersion is the current schema version for TownConfig.
 // Version 2: Added Owner and PublicName fields for federation identity.
 const CurrentTownVersion = 2