Parse transferable days from FK instead of deriving them

The scraper never read "överlåtbara dagar" from Försäkringskassan. It only
visited ansok-och-planera-foraldrapenning#/valjdagar and derived the
reserved/transferable split in build_snapshot, assuming transferable days
are spent before reserved ones. On real data that gave 49 for the user and
0 for the partner where FK states 129 and 71.

The assumption cannot be repaired: reserved-first, transferable-first,
proportional and cap-based models were all checked against real figures and
none reproduces FK's accounting (reserved-first fits the partner but is 10
days off for the user). FK publishes the real numbers per parent per tier on
the min-foraldrapenning page, which the scraper had never visited.

- Scrape the "Dagar ni kan föra över" panel after the valjdagar extraction,
  summing sjukpenningnivå + lägstanivå per parent. The totals are not
  literals on the page. Parse only direct-child <p> elements: the first
  group embeds a tooltip with decoy "45 dagar"/"90 dagar" text.
- build_snapshot accepts the reported value and derives reserved days from
  it; the old arithmetic remains only as a fallback. An implausible FK value
  degrades to that fallback rather than failing the fetch.
- Record provenance in transferable_days_reported (migration 006) and badge
  derived values as estimates in the dashboard breakdown. Drop the footnote's
  claim that at most 150 days are transferable — real data contradicts it as
  a per-family figure.
- Select the child's section by name when FK lists several; never guess.

Verified against a live BankID scrape: scraped 240/101/139 with 129
transferable, deduced partner 240/169/71 with 71, both flagged as reported.

Incidental fixes found along the way:

- The fetch router never forwarded the partner's transferable figure to
  persist_partner_deduction, so the partner's stored snapshot would have kept
  the flawed split even once the parse landed.
- 'deduced' snapshots were labelled "Manually entered" by a two-way ternary
  over a three-value union. Replaced with a compiler-checked exhaustive map.
- Alembic resolved its database from alembic.ini alone, ignoring
  APP_SQLITE_PATH, so migrations silently targeted the developer's real
  database even when pointed elsewhere. env.py now resolves it, preferring
  -x sqlalchemy.url, then a real APP_SQLITE_PATH, then the ini value.
- backend/captures/ was not ignored: the root pattern was anchored as
  /captures/ despite a comment saying scraper dumps must never be tracked.
- CLAUDE.md quoted test counts and coverage percentages that had gone stale,
  which made a correct verification report look suspect. Gate thresholds kept.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DXPBfr1v7F71t6QcbHCaaT

backend/app/services/fetch_data_service.py

@@ -118,6 +118,7 @@ async def persist_partner_deduction(
     sjukpenning_left: int,
     lagsta_niva_left: int,
     dubbeldagar_left: int,
+    transferable_days_left: int | None = None,
 ) -> None:
     """Persist a 'deduced' snapshot for the caller's partner, if there is one.
 
@@ -126,7 +127,10 @@ async def persist_partner_deduction(
     `app.scrapers.fk_scraper._deduce_partner`). Takes plain fields rather
     than the scraper's `PartnerDeduction` dataclass to avoid a router/scraper
     import cycle (`fk_scraper` already imports from this module) — the
-    router unpacks it before calling in.
+    router unpacks it before calling in. `transferable_days_left`, when
+    known (FK's own reported figure for the partner), is forwarded to
+    `build_snapshot` so the partner's reserved/transferable split doesn't
+    fall back to the transferable-first assumption either.
 
     A no-op (logged, never raised) unless the workspace has exactly one
     other non-deleted member: with zero, there's no one to persist for; with
@@ -155,6 +159,7 @@ async def persist_partner_deduction(
             sjukpenning_left=sjukpenning_left,
             lagsta_niva_left=lagsta_niva_left,
             dubbeldagar_left=dubbeldagar_left,
+            transferable_days_left=transferable_days_left,
         )
         await parental_leave_repo.create(fetch)
     except Exception as exc: