feat: add pour warning for vapor-phase formulas, improve help text, add doctor check

- Add Phase field to Formula type to indicate recommended instantiation phase
- Add warning in 'bd mol pour' when formula has phase="vapor"
- Improve pour/wisp help text with clear comparison of when to use each
- Add CheckPersistentMolIssues doctor check to detect mol- issues in JSONL
- Update beads-release.formula.json with phase="vapor"

This helps prevent accidental persistence of ephemeral workflow issues.

cmd/bd/cook.go

@@ -649,6 +649,8 @@ func cookFormulaToSubgraphWithVars(f *formula.Formula, protoID string, vars map[
 			}
 		}
 	}
+	// Attach recommended phase from formula (bd-mol cleanup: warn on pour of vapor formulas)
+	subgraph.Phase = f.Phase
 	return subgraph, nil
 }