feat(J): Phase J Self-Improvement Plugin — controlled improvement loop

- New self_improvement plugin: models, services, routes, plugin
- 4 SQLAlchemy models: ImprovementSignal, ImprovementPattern, ImprovementProposal, ImpactMeasurement
- Migration 0132: 4 tables with RLS
- Services: collect_signals, detect_patterns, create_proposal, evaluate_proposal, request_approval, activate_proposal, rollback_proposal, measure_impact
- 11 API routes under /api/v1/improvement/
- Frontend: improvement.ts API client, ImprovementPanel.tsx in AISidebar proactive tab
- 24/24 integration tests pass
- Fix: __init__.py imports Plugin class for discover_builtins() (self_improvement + knowledge)
- Fix: automation plugin register_plugin_contributions skips when no tenant exists

frontend/src/api/improvement.ts

@@ -0,0 +1,195 @@
+/**
+ * React Query hooks for Self-Improvement API.
+ * Follows the pattern from automation.ts.
+ */
+
+import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
+import { apiGet, apiPost } from './client';
+
+// ── Types ──
+
+export interface ImprovementSignal {
+  id: string;
+  source_type: string;
+  signal_kind: string;
+  severity: string;
+  summary: string;
+  confidence: number;
+  pattern_id: string | null;
+  created_at: string | null;
+}
+
+export interface ImprovementPattern {
+  id: string;
+  pattern_kind: string;
+  title: string;
+  description: string;
+  target_type: string;
+  target_name: string;
+  occurrence_count: number;
+  confidence: number;
+  status: string;
+  proposed_action: string;
+  created_at: string | null;
+}
+
+export interface ImprovementProposal {
+  id: string;
+  title: string;
+  description: string;
+  target_type: string;
+  target_name: string | null;
+  status: string;
+  version_number: number;
+  rationale: string;
+  expected_benefit: string;
+  risk_assessment: string;
+  evaluation_score: number;
+  pattern_id: string | null;
+  created_at: string | null;
+  activated_at: string | null;
+}
+
+export interface ProposalDetail extends ImprovementProposal {
+  target_ref_id: string | null;
+  proposed_config: Record<string, any>;
+  previous_config: Record<string, any>;
+  evidence_refs: any[];
+  evaluation_result: Record<string, any>;
+  evaluated_at: string | null;
+  approval_request_id: string | null;
+  approved_by: string | null;
+  approved_at: string | null;
+  rolled_back_at: string | null;
+  rollback_reason: string | null;
+}
+
+interface PaginatedResponse<T> {
+  items: T[];
+  total: number;
+  page: number;
+  page_size: number;
+}
+
+// ── Signal Hooks ──
+
+export function useSignals(page = 1, pageSize = 20, sourceType?: string) {
+  const params = new URLSearchParams({ page: String(page), page_size: String(pageSize) });
+  if (sourceType) params.set('source_type', sourceType);
+  return useQuery({
+    queryKey: ['improvement-signals', page, pageSize, sourceType],
+    queryFn: () => apiGet<PaginatedResponse<ImprovementSignal>>(`/improvement/signals?${params}`),
+  });
+}
+
+export function useCollectSignals() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (body: { since?: string; limit?: number }) => apiPost('/improvement/signals/collect', body),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-signals'] });
+      qc.invalidateQueries({ queryKey: ['improvement-patterns'] });
+    },
+  });
+}
+
+// ── Pattern Hooks ──
+
+export function usePatterns(page = 1, pageSize = 20) {
+  return useQuery({
+    queryKey: ['improvement-patterns', page, pageSize],
+    queryFn: () => apiGet<PaginatedResponse<ImprovementPattern>>(`/improvement/patterns?page=${page}&page_size=${pageSize}`),
+  });
+}
+
+export function useDetectPatterns() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (body: { min_occurrences?: number }) => apiPost('/improvement/patterns/detect', body),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-patterns'] });
+    },
+  });
+}
+
+// ── Proposal Hooks ──
+
+export function useProposals(page = 1, pageSize = 20, status?: string) {
+  const params = new URLSearchParams({ page: String(page), page_size: String(pageSize) });
+  if (status) params.set('status', status);
+  return useQuery({
+    queryKey: ['improvement-proposals', page, pageSize, status],
+    queryFn: () => apiGet<PaginatedResponse<ImprovementProposal>>(`/improvement/proposals?${params}`),
+  });
+}
+
+export function useProposal(id: string) {
+  return useQuery({
+    queryKey: ['improvement-proposal', id],
+    queryFn: () => apiGet<ProposalDetail>(`/improvement/proposals/${id}`),
+    enabled: !!id,
+  });
+}
+
+export function useCreateProposal() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (body: Record<string, any>) => apiPost('/improvement/proposals', body),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+    },
+  });
+}
+
+export function useEvaluateProposal() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (proposalId: string) => apiPost(`/improvement/proposals/${proposalId}/evaluate`, {}),
+    onSuccess: (_data, proposalId) => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+      qc.invalidateQueries({ queryKey: ['improvement-proposal', proposalId] });
+    },
+  });
+}
+
+export function useRequestApproval() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: ({ proposalId, body }: { proposalId: string; body: { approver_id?: string } }) =>
+      apiPost(`/improvement/proposals/${proposalId}/request-approval`, body),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+    },
+  });
+}
+
+export function useActivateProposal() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (proposalId: string) => apiPost(`/improvement/proposals/${proposalId}/activate`, {}),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+    },
+  });
+}
+
+export function useRollbackProposal() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: ({ proposalId, reason }: { proposalId: string; reason?: string }) =>
+      apiPost(`/improvement/proposals/${proposalId}/rollback`, { reason: reason || '' }),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+    },
+  });
+}
+
+export function useMeasureImpact() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (proposalId: string) => apiPost(`/improvement/proposals/${proposalId}/measure`, {}),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['improvement-proposals'] });
+    },
+  });
+}