feat: add architecture docs, fix code issues from review, add analyze_lint script

Architecture docs (docs/architecture/):
- overview.md: package purpose, exports, terminology, design decisions, gaps
- metagraph.md: core graph model, schema types, SchemaBuilder, validation
- sqlite-host.md: SQLite tables, common columns, relations, concurrency model
- encrypted-data.md: encrypted data as a node type, AES-256-GCM crypto utility design

Code fixes from architecture review:
- Remove ConfigSchema duplication in graphTypes.ts (import GraphConfig from types.ts)
- Add missing SelectNodeSchema/SelectNode to nodes.ts
- Fix InsertEdge.key to be Optional (match nullable DB column)
- Replace TypeScript enums with as const objects (GRAPH_STATUS, GRAPH_BASE_TYPE)
- Add verbatim-module-syntax to lint exclusions (TypeBox false positive)
- Add @std/flags and @std/path to deno.json imports

Infrastructure:
- Add scripts/analyze_lint.ts from @ade for grouped lint analysis
- Add deno task lint:analyze
- Update AGENTS.md with architecture doc references, enum convention, crypto todo

src/sqlite/tables/nodes.ts

@@ -1,5 +1,5 @@
 import { sqliteTable, text, unique } from "drizzle-orm/sqlite-core";
-import { createInsertSchema } from "@alkdev/drizzlebox";
+import { createInsertSchema, createSelectSchema } from "@alkdev/drizzlebox";
 import { Type, type Static } from "@alkdev/typebox";
 import { commonCols } from "./common.ts";
 import { graphs } from "./graphs.ts";
@@ -15,6 +15,15 @@ export const nodes = sqliteTable("nodes", {
   graphKeyIdx: unique().on(table.graphId, table.key),
 }));
 
+export const SelectNodeSchema = createSelectSchema(nodes, {
+  attributes: AttributesSchema,
+  metadata: Type.Object({}, { additionalProperties: true }),
+  createdAt: Type.Date(),
+  updatedAt: Type.Date(),
+});
+
+export type SelectNode = Static<typeof SelectNodeSchema>;
+
 export const InsertNodeSchema = createInsertSchema(nodes, {
   key: Type.String({ minLength: 1 }),
   attributes: AttributesSchema,