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/services/access.py

@@ -21,6 +21,7 @@ from datetime import datetime, timezone
 from fastapi import Depends, HTTPException, status
 
 from app.auth import CurrentUser, require_auth
+from app.config import get_settings
 from app.models import User
 
 # How many hours of news the free tier sees. Paid sees whatever the
@@ -76,13 +77,22 @@ def paid_status(user: User | None) -> PaidStatus:
 
 def is_paid_active(principal: CurrentUser | User | None) -> bool:
     """True if the principal has paid-tier access right now. Admin
-    bearer-token (``CurrentUser.is_admin=True``) always passes."""
+    bearer-token (``CurrentUser.is_admin=True``) always passes.
+
+    When ``SUBSCRIPTIONS_ENABLED=False`` the subscription system is paused:
+    any authenticated principal is treated as paid (free-for-all). Anonymous
+    callers still return False so ``require_paid`` continues to enforce auth.
+    """
     if principal is None:
         return False
     if isinstance(principal, CurrentUser):
         if principal.is_admin:
             return True
+        if not get_settings().SUBSCRIPTIONS_ENABLED:
+            return principal.user is not None
         return paid_status(principal.user).active
+    if not get_settings().SUBSCRIPTIONS_ENABLED:
+        return True
     return paid_status(principal).active