docs: Clarify formulas are JSON, add distillation and sharing docs

- Fix YAML → JSON references in formula.go and types.go
- Update MOLECULES.md with ephemeral proto architecture
- Add Distillation section: extract formulas from completed work
- Add Sharing section: Mol Mall formula marketplace
- Update Layer Cake diagram to show ephemeral proto flow

Related: bd-1dez (Mol Mall epic)

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

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

cmd/bd/formula.go

@@ -18,8 +18,8 @@ var formulaCmd = &cobra.Command{
 	Short: "Manage workflow formulas",
 	Long: `Manage workflow formulas - the source layer for molecule templates.
 
-Formulas are YAML/JSON files that define workflows with composition rules.
-They are "cooked" into proto beads which can then be poured or wisped.
+Formulas are JSON files (.formula.json) that define workflows with composition rules.
+They are "cooked" into ephemeral protos which can then be poured or wisped.
 
 The Rig → Cook → Run lifecycle:
   - Rig: Compose formulas (extends, compose)