feat(topology): cm-topology crate + architecture doc (Phases 0–1)

Foundation for the dynamic agentic-topologies platform (see
docs/topology-platform.md), porting agentorg's topology modeling into pure Rust:

- TopologyKind: curated 12-kind taxonomy (hierarchical, flat, pipeline, swarm,
  mesh, hub_spoke, ring, star_moe, market, blackboard, debate, holacratic).
- TopologyGraph: role-slot nodes + typed edges, with validation.
- adapter: normalize a loose JSON spec → validated graph (fills edge kinds).
- classifier: structural metrics (density, hub dominance, clustering, diameter,
  hierarchy score) → inferred kind + confidence (tree→hierarchical, line→pipeline,
  cycle→ring, star→hub_spoke, complete→mesh, empty→flat).
- heuristics: per-kind role distributions (ported from topology_manager.py).

Pure, offline, dependency-light (serde/thiserror). 17 unit tests, clippy clean.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

crates/cm-topology/src/lib.rs

@@ -0,0 +1,44 @@
+//! Organizational topologies for agentic systems — pure, offline modeling.
+//!
+//! A [`TopologyGraph`] describes *who talks to whom and who decides* in a
+//! system of agents (claws). It is a description only: execution semantics
+//! (and the §15 safety gates) live in the orchestrator, never here.
+//!
+//! This crate is dependency-light (serde + thiserror) and has no I/O, so it
+//! doubles as a reusable library for benchmarking/topology research.
+//!
+//! Modules:
+//! - [`kind`]      — the curated [`TopologyKind`] taxonomy.
+//! - [`graph`]     — the [`TopologyGraph`] data model + validation.
+//! - [`adapter`]   — normalize a loose JSON/YAML spec into a graph.
+//! - [`classifier`]— infer a topology kind from a graph's structure.
+//! - [`heuristics`]— per-kind role distributions / optimization weights.
+
+mod adapter;
+mod classifier;
+mod graph;
+mod heuristics;
+mod kind;
+
+pub use adapter::{from_json, to_json};
+pub use classifier::{classify, Classification, GraphMetrics};
+pub use graph::{Edge, EdgeKind, Node, TopologyGraph};
+pub use heuristics::{heuristics, Heuristics};
+pub use kind::TopologyKind;
+
+/// Errors produced while building or validating a topology.
+#[derive(Debug, thiserror::Error, PartialEq, Eq)]
+pub enum TopologyError {
+    /// The graph has no nodes.
+    #[error("topology has no nodes")]
+    Empty,
+    /// An edge references a node id that does not exist.
+    #[error("edge references unknown node: {0}")]
+    UnknownNode(String),
+    /// Two nodes share an id.
+    #[error("duplicate node id: {0}")]
+    DuplicateNode(String),
+    /// The input spec could not be parsed.
+    #[error("invalid spec: {0}")]
+    Spec(String),
+}