docs: restructure architecture docs to flowgraph pattern

- Create decisions/ directory with 32 numbered ADRs (ADR-001 through ADR-032)
  extracted from inline DD/SD/ED/SE decision sections
- Create open-questions.md with 16 OQs organized by theme, cross-referenced
  to ADRs, with status tracking (resolved/open)
- Create README.md as architecture index with doc table, ADR table, and
  lifecycle status definitions (draft/reviewed/stable/deprecated)
- Replace inline decision sections in all spec docs with ADR reference tables
- Replace inline open questions with OQ references to centralized tracker
- Update frontmatter: metagraph-module.md, overview.md, sqlite-host.md → reviewed;
  schema-evolution.md and encrypted-data.md remain draft
- DD1-DD10 → ADR-009 through ADR-018
- D1-D8 → ADR-001 through ADR-008
- SD1-SD5 → ADR-019 through ADR-023 (SD5 folded into ADR-006/008)
- ED1-ED5 → ADR-023 through ADR-027
- SE1-SE5 → ADR-028 through ADR-032

docs/architecture/decisions/014-dereferenced-entry-schemas.md

@@ -0,0 +1,24 @@
+# ADR-014: Repository stores dereferenced entry schemas
+
+## Status
+
+Accepted
+
+## Context
+
+When a Module entry uses `Module.Import()`, the entry's JSON Schema embeds the referenced Module's `$defs`. For example, `CallGraph` importing `FlowGraph.Import("CallStatus")` includes all of `FlowGraph`'s definitions in the JSON Schema output. Storing this in every `node_types` row would duplicate the entire referenced Module.
+
+## Decision
+
+The repository layer stores **dereferenced entry schemas** — each `node_types` row gets its entry's resolved JSON Schema with just the transitive `$defs` it needs, not the entire importing Module's definitions. This avoids storage bloat and version coupling between packages.
+
+## Consequences
+
+- Each DB row stores 1–3 KB of JSON Schema (just its own entry + transitive refs)
+- A full graph type's schemas total ~10–50 KB in the DB, negligible compared to node/edge data
+- No version coupling — a `FlowGraph` version change doesn't require updating all CallGraph rows
+- `moduleToDbSchema()` performs the dereferencing at write time
+
+## References
+
+- [metagraph-module.md](../metagraph-module.md)