compliance: flag-gate AI portfolio + cloud sync + Stripe; de-risk prompts; harden reviewer

Implements docs/read-markets-compliance-changes.md as flag-gated changes
(no deletions) so paused features stay in the tree for future re-enable.
All four flags default False so a fresh deploy is compliance-safe.

- New env flags: PORTFOLIO_AI_ENABLED, PORTFOLIO_SYNC_ENABLED,
  TICKER_UNIVERSE_AGGREGATE_ENABLED, SUBSCRIPTIONS_ENABLED.
- Gates: /api/analyze, /api/portfolio/sync*, /api/stripe/*, /pricing,
  ticker_universe writes, portfolio_analysis.analyse(). is_paid_active()
  returns True for any auth'd user when subscriptions are paused.
- Prompts (PROMPT_VERSION 10): universal _COMPLIANCE_RIDER prepended to
  every system prompt; watch list removed; price-target / close-above-below
  / trigger / forward-state-as-description rules added; SPECULATIVE
  pivoted to regime-only scenarios; daily + weekly digests tightened.
- Reviewer: deterministic regex/lexicon pre-check fail-closed under the
  Haiku call; portfolio rider gated by PORTFOLIO_AI_ENABLED; base prompt
  sharpened for forward-state and MAR forward-opinion patterns;
  ReviewerVerdict audit table; generate_with_review retry helper.
- Migration 0026: purge portfolio_sync + ticker_universe; create
  reviewer_verdicts.
- Copy: MAR cite fixed to Art 3(1)(35) + Art 20 + Del Reg 2016/958;
  portfolio reframed as browser-only viewer in disclaimer / privacy /
  terms / about / pricing / landing (en + it). TODO(legal) marker for
  lawyer sign-off on disclaimer.
- Tests: 13 lexicon + 6 reviewer compliance regressions; conftest enables
  all flags so existing 402 tests still cover their code paths.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/routers/universe.py

@@ -41,6 +41,7 @@ from app.models import Quote, QuoteDaily
 from app.services import fx, portfolio_analysis, ticker_universe
 from app.services.access import require_paid
 from app.services.csv_import import CSVImportError, parse_t212_csv
+from app.services.feature_flags import require_flag
 from app.services.instrument_map import resolve_slice
 from app.services.market import fetch as market_fetch
 
@@ -338,7 +339,10 @@ async def parse_portfolio(
 # ---------------------------------------------------------------------------
 
 
-@router.post("/analyze")
+@router.post(
+    "/analyze",
+    dependencies=[Depends(require_flag("PORTFOLIO_AI_ENABLED"))],
+)
 async def analyze_portfolio(
     request: Request,
     session: AsyncSession = Depends(get_session),
@@ -349,8 +353,8 @@ async def analyze_portfolio(
     is persisted. The ai_calls ledger row records tokens + cost, never
     holdings.
 
-    Gated behind ``require_paid``: free-tier users get 402.
-    Admin bearer-token bypasses the gate for testing."""
+    Gated behind ``PORTFOLIO_AI_ENABLED`` (404 when off) and ``require_paid``
+    (402 for free tier when subscriptions are active)."""
     # Read JSON body manually so we can enforce a hard size cap. FastAPI's
     # default body limit is generous; we want tighter control here.
     body = await request.body()