refactor(mol): remove bd mol spawn - use pour/wisp only (bd-8y9t)

Remove the spawn command from bd mol. Proto instantiation now uses:
- bd pour <proto> - Instantiate as persistent mol (liquid phase)
- bd wisp create <proto> - Instantiate as ephemeral wisp (vapor phase)

Rationale:
- 'spawn' doesn't fit the chemistry metaphor
- Two phase transitions (pour/wisp) are clearer than one command with flags
- Avoids confusion about defaults

Changes:
- Delete mol_spawn.go
- Update mol.go, mol_catalog.go, mol_distill.go to reference pour/wisp
- Update pour.go and wisp.go to remove 'Equivalent to spawn' comments
- Update info.go changelog entries
- Update CHANGELOG.md, ARCHITECTURE.md, DELETIONS.md

Closes bd-8y9t

cmd/bd/pour.go

@@ -12,7 +12,6 @@ import (
 )
 
 // pourCmd is a top-level command for instantiating protos as persistent mols.
-// It's the "chemistry" alias for: bd mol spawn <proto> --pour
 //
 // In the molecular chemistry metaphor:
 //   - Proto (solid) -> pour -> Mol (liquid)
@@ -32,8 +31,6 @@ Use pour for:
   - Important work needing audit trail
   - Anything you might need to reference later
 
-Equivalent to: bd mol spawn <proto> --pour
-
 Examples:
   bd pour mol-feature --var name=auth    # Create persistent mol from proto
   bd pour mol-release --var version=1.0  # Release workflow