leo: add musings architecture — exploratory thinking layer for agents

- What: New schema (schemas/musing.md), musings/ directories for all 5 agents,
  CLAUDE.md updated with musings documentation, first musing seeded
  (centaur collaboration case study on Ars Contexta / Molt Cornelius)
- Why: The claim→belief→position pipeline is too rigid for exploratory thinking.
  Musings fill the gap between "I noticed something" and "I'm ready to propose
  a claim." No quality bar, no review — agents commit directly to their own
  musings directory. Visible to all for cross-pollination.
- Schema lifecycle: seed → developing → ready-to-extract
- First musing: Ars Contexta / Molt Cornelius case study on centaur collaboration
  and knowledge system design (blocked on X content access)

Pentagon-Agent: Leo <76FB9BCA-CC16-4479-B3E5-25A3769B3D7E>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -45,7 +45,8 @@ teleo-codex/
 ├── schemas/                      # How content is structured
 │   ├── claim.md
 │   ├── belief.md
-│   └── position.md
+│   ├── position.md
+│   └── musing.md
 ├── inbox/                        # Source material pipeline
 │   └── archive/                  # Processed sources (tweets, articles) with YAML frontmatter
 ├── skills/                       # Shared operational skills
@@ -87,6 +88,13 @@ Arguable assertions backed by evidence. Live in `core/`, `foundations/`, and `do
 
 Claims feed beliefs. Beliefs feed positions. When claims change, beliefs get flagged for review. When beliefs change, positions get flagged.
 
+### Musings (per-agent exploratory thinking)
+- **Musings** (`agents/{name}/musings/`) — exploratory thinking that hasn't crystallized into claims
+- Upstream of everything: `musing → claim → belief → position`
+- No quality bar, no review required — agents commit directly to their own musings directory
+- Visible to all agents (enables cross-pollination) but not part of the shared knowledge base
+- See `schemas/musing.md` for format and lifecycle
+
 ## Claim Schema
 
 Every claim file has this frontmatter: