feat: Rename 'wisp' to 'ephemeral' in beads API (bd-o18s)

BREAKING CHANGE: API field and CLI command renamed

- types.Issue.Wisp → types.Issue.Ephemeral
- JSON field: "wisp" → "ephemeral"
- CLI: bd wisp → bd ephemeral
- Flags: --wisp → --ephemeral
- ID prefix: wisp → eph

The SQLite column already uses 'ephemeral' so no schema migration needed.

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

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

cmd/bd/template.go

@@ -42,10 +42,10 @@ type InstantiateResult struct {
 
 // CloneOptions controls how the subgraph is cloned during spawn/bond
 type CloneOptions struct {
-	Vars     map[string]string // Variable substitutions for {{key}} placeholders
-	Assignee string            // Assign the root epic to this agent/user
-	Actor    string            // Actor performing the operation
-	Wisp     bool              // If true, spawned issues are marked for bulk deletion
+	Vars      map[string]string // Variable substitutions for {{key}} placeholders
+	Assignee  string            // Assign the root epic to this agent/user
+	Actor     string            // Actor performing the operation
+	Ephemeral bool              // If true, spawned issues are marked for bulk deletion
 	Prefix   string            // Override prefix for ID generation (bd-hobo: distinct prefixes)
 
 	// Dynamic bonding fields (for Christmas Ornament pattern)
@@ -327,7 +327,7 @@ Example:
 			Vars:     vars,
 			Assignee: assignee,
 			Actor:    actor,
-			Wisp:     false,
+			Ephemeral:     false,
 		}
 		var result *InstantiateResult
 		if daemonClient != nil {
@@ -713,7 +713,7 @@ func cloneSubgraphViaDaemon(client *rpc.Client, subgraph *TemplateSubgraph, opts
 			AcceptanceCriteria: substituteVariables(oldIssue.AcceptanceCriteria, opts.Vars),
 			Assignee:           issueAssignee,
 			EstimatedMinutes:   oldIssue.EstimatedMinutes,
-			Wisp:               opts.Wisp,
+			Ephemeral:               opts.Ephemeral,
 			IDPrefix:           opts.Prefix, // bd-hobo: distinct prefixes for mols/wisps
 		}
 
@@ -960,7 +960,7 @@ func cloneSubgraph(ctx context.Context, s storage.Storage, subgraph *TemplateSub
 				IssueType:          oldIssue.IssueType,
 				Assignee:           issueAssignee,
 				EstimatedMinutes:   oldIssue.EstimatedMinutes,
-				Wisp:               opts.Wisp,   // bd-2vh3: mark for cleanup when closed
+				Ephemeral:               opts.Ephemeral,   // bd-2vh3: mark for cleanup when closed
 				IDPrefix:           opts.Prefix, // bd-hobo: distinct prefixes for mols/wisps
 				CreatedAt:          time.Now(),
 				UpdatedAt:          time.Now(),