feat: Add mol_type schema field for molecule type classification (bd-oxgi)

Add mol_type field to beads for swarm coordination:
- Values: 'swarm' (multi-polecat), 'patrol' (recurring ops), 'work' (default)
- Nullable, defaults to empty string (treated as 'work')

Changes:
- Add mol_type column to SQLite schema and migration 031
- Add MolType type with IsValid() validation in types.go
- Update insertIssue/GetIssue to handle mol_type
- Add --mol-type flag to create command
- Add mol_type filtering to list and ready commands
- Update RPC protocol for daemon mode support
- Update test schema in migrations_test.go

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

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

internal/types/types.go

@@ -97,6 +97,9 @@ type Issue struct {
 	LastActivity *time.Time `json:"last_activity,omitempty"` // Updated on each action (timeout detection)
 	RoleType     string     `json:"role_type,omitempty"`     // Role: polecat|crew|witness|refinery|mayor|deacon
 	Rig          string     `json:"rig,omitempty"`           // Rig name (empty for town-level agents)
+
+	// ===== Molecule Type Fields (swarm coordination) =====
+	MolType MolType `json:"mol_type,omitempty"` // Molecule type: swarm|patrol|work (empty = work)
 }
 
 // ComputeContentHash creates a deterministic hash of the issue's content.
@@ -156,6 +159,9 @@ func (i *Issue) ComputeContentHash() string {
 	w.str(i.RoleType)
 	w.str(i.Rig)
 
+	// Molecule type
+	w.str(string(i.MolType))
+
 	return fmt.Sprintf("%x", h.Sum(nil))
 }
 
@@ -422,6 +428,25 @@ func (s AgentState) IsValid() bool {
 	return false
 }
 
+// MolType categorizes the molecule type for swarm coordination
+type MolType string
+
+// MolType constants
+const (
+	MolTypeSwarm  MolType = "swarm"  // Swarm molecule: coordinated multi-polecat work
+	MolTypePatrol MolType = "patrol" // Patrol molecule: recurring operational work (Witness, Deacon, etc.)
+	MolTypeWork   MolType = "work"   // Work molecule: regular polecat work (default)
+)
+
+// IsValid checks if the mol type value is valid
+func (m MolType) IsValid() bool {
+	switch m {
+	case MolTypeSwarm, MolTypePatrol, MolTypeWork, "":
+		return true // empty is valid (defaults to work)
+	}
+	return false
+}
+
 // Dependency represents a relationship between issues
 type Dependency struct {
 	IssueID     string         `json:"issue_id"`
@@ -680,6 +705,9 @@ type IssueFilter struct {
 
 	// Parent filtering: filter children by parent issue ID
 	ParentID *string // Filter by parent issue (via parent-child dependency)
+
+	// Molecule type filtering
+	MolType *MolType // Filter by molecule type (nil = any, swarm/patrol/work)
 }
 
 // SortPolicy determines how ready work is ordered
@@ -724,6 +752,9 @@ type WorkFilter struct {
 
 	// Parent filtering: filter to descendants of a bead/epic (recursive)
 	ParentID *string // Show all descendants of this issue
+
+	// Molecule type filtering
+	MolType *MolType // Filter by molecule type (nil = any, swarm/patrol/work)
 }
 
 // StaleFilter is used to filter stale issue queries