Update dependency analysis artifacts

Generated comprehensive static dependency analysis for g3 workspace:

- graph.json: 108 nodes (9 crates, 99 files), 186 edges
- graph.summary.md: Overview with metrics, entrypoints, fan-in/fan-out rankings
- sccs.md: No cycles detected (DAG structure confirmed)
- layers.observed.md: 4-layer crate hierarchy identified
- hotspots.md: ui_writer.rs (15 fan-in), agent_mode.rs (13 fan-out) as key nodes
- limitations.md: Documents extraction methodology and caveats

Updated AGENTS.md with artifact documentation table.

Agent: euler

AGENTS.md

@@ -67,3 +67,18 @@ These areas have subtle bugs if modified incorrectly:
 3. **"Tool results are always small"** - File reads can return megabytes
 4. **"Sessions persist across runs"** - Sessions are ephemeral by default
 5. **"All platforms are equal"** - macOS has more features (Vision, Accessibility)
+
+## Dependency Analysis Artifacts
+
+The `analysis/deps/` directory contains static analysis artifacts generated by the euler agent:
+
+| File | Purpose |
+|------|--------|
+| `graph.json` | Canonical dependency graph with nodes (crates, files) and edges (imports) |
+| `graph.summary.md` | One-page overview with metrics, entrypoints, and top fan-in/fan-out nodes |
+| `sccs.md` | Strongly connected components (dependency cycles) analysis |
+| `layers.observed.md` | Observed layering structure derived from dependency direction |
+| `hotspots.md` | Files with disproportionate coupling (high fan-in or fan-out) |
+| `limitations.md` | What could not be observed and what may invalidate conclusions |
+
+These artifacts are useful for understanding coupling, planning refactors, and identifying architectural boundaries.