Rework balances around per-parent days left and deduce the partner from FK

Manual entry now takes one parent's sjukpenningnivå, lägstanivå and
dubbeldagar left (plus optional reserved days) and derives the rest in
build_snapshot, shared with the scraper. The scraper also reads the
family panel and exposes a partner deduction; with two parents it is
saved as a 'deduced' snapshot (migration 002). Parent count is the single
source of entitlement: one member gets 480 days and 96 savable at age 4,
two get 240 and 48 each. Workspaces are capped at two parents.

Also lands the in-flight squash of migrations 002–011 into the initial
schema and the removal of planning_mode.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

backend/README.md

@@ -1,8 +1,12 @@
 # Backend — Föräldraledigplannerare
 
 FastAPI + Python 3.14, packages managed with `uv`. Layered architecture
-(entities → repositories → services → routers) with dependency injection so the
-database backend (SQLite now, Postgres later) is swappable.
+(entities → repositories → services → routers) with dependency injection.
+**Postgres is a partial stub, not a working swap today:** only
+`repositories_impl/postgres/vacation_days_repository.py` exists; every other
+`app/dependencies.py` repository factory raises `ValueError` for any
+`database_type` other than `"sqlite"`. SQLite is the only usable backend
+until the remaining Postgres repositories land.
 
 ## Setup
 
@@ -13,16 +17,55 @@ uv run pytest           # run tests with coverage
 uv run ruff check .     # lint
 ```
 
+`uv run pytest` alone does not enforce a coverage floor (`pyproject.toml`'s
+`addopts` only requests a report). CI additionally passes
+`--cov-fail-under=80` (see the root `CLAUDE.md`) — a locally green run can
+still fail in CI if coverage dropped.
+
 ## Configuration
 
-Key env vars (prefix `APP_`, see `.env.example`):
+Env vars (prefix `APP_`, nested via `__`; see `.env.example`). `Settings`
+lives in `app/config.py` — that file's module docstring mentions a
+`HMAC_PEPPER` setting; **no such setting exists**, so do not look for it here
+or set it expecting an effect.
 
 - `APP_ENV` — `development` (default) | `test` | `production`. In production,
   `Settings` refuses to start unless `APP_JWT_SECRET` is a random value of at
   least 32 characters (the shipped dev default is rejected). Production also
   disables `/docs`, `/redoc`, and `/openapi.json`.
+- `APP_DATABASE_TYPE` — `sqlite` (default) | `postgres` (not usable yet — see above).
+- `APP_SQLITE_PATH` — default `./foraldraledig.db`.
+- `APP_CORS_ORIGINS` — JSON list; default `["http://localhost:5173"]`.
 - `APP_JWT_SECRET` — required to be a strong, random secret in production.
+- `APP_JWT_ALGORITHM` — default `HS256`.
+- `APP_JWT_ACCESS_TOKEN_EXPIRE_MINUTES` — default `15`.
+- `APP_JWT_REFRESH_TOKEN_EXPIRE_DAYS` — default `7`.
 - `APP_LOG_LEVEL` — default `INFO`.
+- `APP_SCRAPER_ENABLED` — **defaults to `true`.** Legal/ToS review of FK scraping + BankID
+  automation completed 2026-06; the scraper is cleared for use. Set to `false` in any
+  environment without Playwright's Chromium installed (`uv run playwright install chromium`).
+- `APP_SCRAPER_HEADLESS` — default `true`.
+- `APP_SCRAPER_SESSION_TTL_SECONDS` — default `180`; auto-cancels a stalled scraper session.
+- `APP_SCRAPER_DEBUG_ENABLED` — default `false`. **When enabled, writes personal data to disk**
+  (an HTML dump + full-page screenshot of the logged-in FK page — name, balances, payout
+  amounts). Requires `APP_SCRAPER_DEBUG_DIR` to also be set. Local debugging only; never enable
+  in a shared or production environment.
+- `APP_SCRAPER_DEBUG_DIR` — where debug artifacts are written when the above is enabled.
+- `APP_SCRAPER_DEBUG_DUMP_ON_SUCCESS` — default `false`. Also writes the same debug artifacts
+  (HTML + full-page screenshot) after a **successful** extraction, not just on error — a capture
+  aid for confirming FK's real DOM (e.g. the family panel structure `app/scrapers/fk_scraper.py`
+  currently assumes). Same personal-data warning as `APP_SCRAPER_DEBUG_ENABLED` applies; only
+  takes effect when both `APP_SCRAPER_DEBUG_ENABLED` and `APP_SCRAPER_DEBUG_DIR` are also set.
+- `APP_SCRAPER_RESULT_RETENTION_SECONDS` — default `300`; how long a finished scraper session's
+  result stays in memory before being purged.
+- `APP_RULES__*` — the Swedish parental-leave rule constants (`LeaveRules`, nested under `rules`),
+  overridable per field, e.g. `APP_RULES__MAX_SAVABLE_DAYS_AT_AGE_4=96`. Defaults: 390
+  sjukpenning days, 90 lägstanivå days, 90 reserved days/parent, 60 max dubbeldagar over the
+  first 15 months, 96 max savable at age 4 (48 per parent when the child has two or more
+  parents — see `resolve_age4_savable_cap`), age-12 hard expiry, 6 preschool planning days/year,
+  25 statutory vacation days/year, 20 minimum vacation days/year that must be taken. These are
+  common-case figures only — children born before 2014, multiples, and single custody differ and
+  are not modeled.
 
 ## Layout