Align storage & architecture specs with published npm libraries

Systematically compared @alkdev/taskgraph, @alkdev/operations, and
@alkdev/flowgraph against storage/arch specs and fixed all mismatches.

Key changes:

Tasks (storage/tasks.md + ADR-011):
- Rename TaskFrontmatter → TaskInput to match library export
- Fix dependsOn (was depends_on) in field mappings — library uses
  camelCase; parseFrontmatter normalizes YAML snake_case on input
- Document DependencyEdge shape {from, to, qualityRetention?} and
  DB↔library field mapping
- Document graph node vs DB column distinction (TaskGraphNodeAttrs
  is a subset of TaskInput)
- Fix default risk fallback from low → medium (matches resolveDefaults)
- Fix cross-project guard column references (dependentTaskId, not taskId)
- Clarify @alkdev/taskgraph TS is source of truth; frontmatter is for
  LLM output parsing and legacy imports, not Rust CLI
- Add complete library exports reference

Operations (storage/spokes.md + operations.md):
- Add version, title, _meta columns to operations table (required by
  OperationSpec, were missing)
- Fix type casing: query/mutation/subscription (lowercase, matching
  OperationType runtime values)
- Make outputSchema and accessControl NOT NULL (matching library)
- Document ErrorDefinition shape {code, description, schema, httpStatus?}
- Document _meta vs commonCols.metadata distinction
- Add registerAll, get, getHandler, getByName, list, subscribe methods
- Fix buildCallHandler signature ({ registry, callMap })
- Fix OperationType values (lowercase)

Call graph (storage/call-graph.md + call-graph.md):
- Change operationId to NOT NULL with RESTRICT FK (was nullable/SET NULL)
  — matches flowgraph's required CallNodeAttrs.operationId
- Document sentinel __removed__ operation strategy for deletions
- Document ISO 8601 string ↔ timestamptz conversion requirement
- Rewrite CallEventMap to match actual library: flat dot-notation keys,
  timestamp on all events, nested error structure, optional output on
  completed event
- Remove call.running event (doesn't exist in library) — hub calls
  updateStatus(running) directly on dispatch
- Fix buildCallHandler({ registry, callMap }) signature
- Fix PendingRequestMap constructor (positional EventTarget)
- Add updateCall/removeCall/graph methods to API summary
- Document abort cascade as hub logic, not flowgraph logic
- Add open questions for operation deletion and reactive vs call graph
  semantics

Table reference (storage/table-reference.md):
- Update call_graph_nodes.operationId cascade to RESTRICT
- Update operations.type comment to lowercase
- Update status enum reference

docs/decisions/ADR-011-dual-task-representation.md

@@ -38,9 +38,9 @@ We choose **Option 3: Database as source of truth, files as authoring surface**.
 
 ### Key Design Principles
 
-1. **Every taskgraph frontmatter field is a proper DB column** — no fields relegated to JSONB `metadata`. `priority`, `assignee`, `dueAt`, `tags` get dedicated columns because they're queryable and filterable in coordinator workflows.
+1. **Every taskgraph frontmatter field is a proper DB column** — no fields relegated to JSONB `metadata`. `priority`, `assignee`, `dueAt`, `tags` get dedicated columns because they're queryable and filterable in coordinator workflows. The library type is `TaskInput` (TypeScript equivalent of the Rust `TaskFrontmatter`).
 
-2. **Categorical fields are nullable, not NOT NULL with defaults** — `scope`, `risk`, `impact`, `level` are nullable (NULL = not yet assessed). This preserves the distinction between "deliberately assessed as low" and "nobody filled this in." Taskgraph itself uses `Option<TaskScope>` etc.
+2. **Categorical fields are nullable, not NOT NULL with defaults** — `scope`, `risk`, `impact`, `level` are nullable (NULL = not yet assessed). This preserves the distinction between "deliberately assessed as low" and "nobody filled this in." The library uses `Type.Optional(Nullable(Enum))` on `TaskInput`, matching this model. For analysis, `resolveDefaults()` uses `medium` as the default risk (replacing the old `low` default) and `narrow`/`isolated` for scope/impact — these are computational fallbacks, not DB defaults, making unassessed tasks more visible in analysis rather than appearing optimistically safe.
 
 3. **No `parentId`** — Grouping is handled by `path` (a nullable text column for scoped queries like `WHERE path LIKE 'implementation/%'`). Dependencies are in `task_dependencies`. These are separate concepts.
 
@@ -73,4 +73,4 @@ We choose **Option 3: Database as source of truth, files as authoring surface**.
 - ADR-001: JSONB data columns vs individual columns (same principle — proper columns for queryable fields)
 - Cost-benefit framework: taskgraph framework docs
 - Task storage: `docs/architecture/storage/tasks.md`
-- taskgraph TaskFrontmatter: taskgraph source
+- taskgraph TaskInput: taskgraph source