docs: Clarify formula vs molecule semantics - formulas are NOT instructions

PROBLEM: Agents were reading formula files directly and manually creating beads
for each step, rather than using the cook→pour→molecule pipeline.

FIXES:
- polecat-CLAUDE.md: Changed "following the formula" to "work through your
  pinned molecule" and added explicit anti-pattern warning
- mol-polecat-work.formula.toml: Added note that formula defines template,
  use bd ready to find step beads
- docs/molecules.md: Added "Common Mistake" section with WRONG/RIGHT examples
- mol-*.formula.toml (5 files): Changed "execute this formula" to "work
  through molecules (poured from this formula)"

The key insight: Formulas are source templates (like source code). You never
read them directly. The cook → pour pipeline creates step beads for you.

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

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

.beads/formulas/mol-dep-propagate.formula.toml

@@ -1,7 +1,7 @@
 description = """
 Propagate cross-rig dependency resolution.
 
-Dogs execute this formula when dependencies resolve across rig boundaries.
+Dogs work through molecules (poured from this formula) when dependencies resolve across rig boundaries.
 When an issue in one rig closes, dependent issues in other rigs may unblock.
 This formula handles:
 - Finding cross-rig dependents