fix: the membership status vocabulary moves beside Membership, so the Patreon client never imports the roster

240f11c made PatreonClient._membership import has_paid_access from membership_roster. test_gated_reason::test_no_fetch_path_can_read_the_roster failed on it, correctly: native_ingest_common is a fetch root, patreon_client is reachable from it, and no fetch path may be able to reach the roster. The roster is allowed to explain a skip, never to cause one.

MEMBERSHIP_STATUS and has_paid_access are pure platform knowledge with no database behind them. They move to native_ingest_common, next to the Membership type they interpret (the same move C7 made for Membership itself). membership_roster, membership_reconcile, patreon_client and the tests import them from there. There is no re-export from membership_roster.

The guard is unchanged. The lapsed-orphan skip from 240f11c stays as it was.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SHQB1YukL3VyvMK8rcbmV9

backend/app/services/membership_roster.py

@@ -20,8 +20,10 @@ own word — `active_patron`, not some normalised FC value. The mapping from
 those words to FC's meaning is a read-site concern and belongs in code that can
 be corrected without a migration, because the vocabulary comes from whatever
 each platform says and will be discovered per platform rather than designed up
-front. `MEMBERSHIP_STATUS` below is a place for that knowledge to accumulate as
-platforms are characterised; it is deliberately empty of guesses today.
+front. `native_ingest_common.MEMBERSHIP_STATUS` is where that knowledge
+accumulates as platforms are characterised, and it holds no guesses. It lives
+there rather than here because platform clients need it, and a client may not
+import this module (test_gated_reason.py).
 """
 
 from __future__ import annotations
@@ -35,78 +37,10 @@ from sqlalchemy.dialects.postgresql import insert as pg_insert
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from ..models import MembershipSync, PlatformMembership, Source
+from .native_ingest_common import has_paid_access
 
 log = logging.getLogger(__name__)
 
-# Platform word -> whether the account currently has paid access.
-#
-# Every entry here must come from a CHARACTERISED response, never from API docs
-# or a plausible guess — project rule 130, and inventing a status before seeing
-# it in a real payload is exactly the failure it names.
-#
-# patreon: from a live capture of the operator's own session, 2026-09-10
-# (Scribe note #3886). Only two values were OBSERVED in `patron_status` and
-# only those two are here.
-#
-# `declined_patron` is deliberately ABSENT even though it looks obviously
-# right. It appears in the request's `filter[membership_type]`, and the capture
-# proved that filter is NOT the same vocabulary as the attribute — a row
-# selected by the filter as `free_member` came back with
-# `patron_status: former_patron`, a word the filter does not contain. Reading
-# the filter as an enum is the specific mistake the capture caught; adding
-# `declined_patron` on the strength of it would be repeating that mistake one
-# step later.
-#
-# Unknown words are NOT an error: an unrecognised status means the roster
-# records evidence it cannot yet interpret, which is a better state than
-# dropping the row or asserting a meaning for it.
-#
-# subscribestar: from a live capture of the account's /subscriptions page,
-# 2026-09-13 (Scribe note #3989). SubscribeStar gives NO per-row status word —
-# a membership's state is which of two tables it sits in — so the "word" stored
-# is the table card's own `data-identifier`, verbatim. Those two identifiers are
-# the whole vocabulary; there is nothing further to characterise later.
-MEMBERSHIP_STATUS: dict[str, dict[str, bool]] = {
-    "patreon": {
-        "active_patron": True,
-        "former_patron": False,
-    },
-    "subscribestar": {
-        "active_subscriptions": True,
-        "cancelled_subscriptions": False,
-    },
-}
-
-
-def has_paid_access(
-    platform: str, status: str | None, *, is_free_member: bool = False,
-) -> bool | None:
-    """Does this membership mean the account currently PAYS for access?
-
-    Returns None for a status this code has not been taught, which callers must
-    treat as "unknown" rather than as False. The difference matters: False says
-    the operator has lost access, and asserting that from an unrecognised word
-    would tell them to cancel a source they are still paying for.
-
-    `is_free_member` is a second axis, not a status, and that is Patreon's
-    design rather than ours: the capture shows a free follow expressed as a
-    boolean alongside `patron_status`, so a "current" membership can still be
-    one nobody is paying for. Taking status alone would report a free follower
-    as a paying patron, and C4 would then never offer to clean it up.
-
-    (Honest limit: the capture contains no ACTIVE free member, so it cannot
-    demonstrate the two axes coming apart. The separation is what the payload's
-    shape says; the sample only shows it is possible, not that it happens.)
-    """
-    if status is None:
-        return None
-    known = MEMBERSHIP_STATUS.get(platform, {}).get(status)
-    if known is None:
-        return None
-    if not known:
-        return False
-    return not is_free_member
-
 
 async def touch_membership(
     session: AsyncSession,