refactor: simplify wisp architecture - single DB with Wisp flag (bd-bkul)

- Remove cross-store squash logic from mol_squash.go
  - Delete runWispSquash() and squashWispToPermanent() functions
  - Simplify runMolSquash() to work with main store only

- Update mol_burn.go to work with main database
  - Remove .beads-wisp/ directory references
  - Look for Wisp=true issues in main store instead

- Update mol_bond.go to use Wisp flag instead of separate store
  - --wisp now creates issues with Wisp=true in main store
  - --pour creates issues with Wisp=false (persistent)
  - Update bondProtoMol signature to accept both flags

- Deprecate wisp storage functions in beads.go
  - WispDirName, FindWispDir, FindWispDatabasePath
  - NewWispStorage, EnsureWispGitignore, IsWispDatabase
  - All marked deprecated with reference to bd-bkul

- Remove obsolete cross-store squash tests
  - TestSquashWispToPermanent
  - TestSquashWispToPermanentWithSummary
  - TestSquashWispToPermanentKeepChildren

All tests pass. Build succeeds.

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

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

cmd/bd/pour.go

@@ -197,7 +197,8 @@ func runPour(cmd *cobra.Command, args []string) {
 		}
 
 		for _, attach := range attachments {
-			bondResult, err := bondProtoMol(ctx, store, attach.issue, spawnedMol, attachType, vars, "", actor, true)
+			// pour command always creates persistent (Wisp=false) issues
+			bondResult, err := bondProtoMol(ctx, store, attach.issue, spawnedMol, attachType, vars, "", actor, false, true)
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "Error attaching %s: %v\n", attach.id, err)
 				os.Exit(1)