srrdb: harvest the srrDB search API into a separate SQLite database

New scope reading the API instead of scraping HTML: one search path per run,
passed raw through --single-uri, and the answer stored as-is into its own
SQLite file created from the embedded schema.

Command line: --single-uri carries the path after /v1/search/
(category:flac/date:today/page:1) and must name a category; --sleep sets the
pause between pages, with the config value as fallback. A day named on the
command line is always fetched again and its dump rewritten, so cron can
refresh today hourly and yesterday daily.

Date placeholders: date:auto walks backwards to the newest day in
[srrdb.floor..yesterday] that has no dump yet, closing holes instead of
declaring the archive covered. date:today, date:yesterday and date:tomorrow
stand for the neighbouring days. Today is never taken by the walk, because a
day still being filled would be frozen by its own dump after the first run.

Dumps are the cursor as well as the record, so a missing dump directory is an
error instead of "nothing harvested yet": a renamed, unmounted or mistyped
directory must not send the run silently back to the beginning. An empty day is
a normal result and is remembered as harvested; API warnings never are, and
they reach the exit code.

Writes go through one transaction, so a day lands completely or not at all.
group and category come from the release line and the search path; status, nfo,
content and synced_at stay NULL. srrdb.log.jsonl records one line per finished
run, srrdb.error_log.jsonl keeps failures and API warnings apart by a kind
field.

Also: the console command contract returns (string, error), so a failing scope
reaches the process exit code and cron can tell a failed run from a successful
one. config/scope/srrdb.yaml is untracked because its paths differ per host.
modernc.org/sqlite replaces the archived libsql client, which only ever talked
to a server. pkg/repository/srrdb.go is split by responsibility and covered by
table-driven tests.

internal/db/srrdb.sql

@@ -0,0 +1,39 @@
+CREATE TABLE IF NOT EXISTS srrdb_releases
+(
+    "release"    TEXT PRIMARY KEY NOT NULL,
+    date       TEXT,
+    created_at TEXT NOT NULL,
+    synced_at  TEXT,
+    category   TEXT NOT NULL DEFAULT '',
+    status     TEXT,
+    group_name TEXT,
+    has_nfo    TEXT,
+    has_srs    TEXT,
+    is_foreign TEXT,
+    imdb_id    TEXT,
+    size       INTEGER,
+    comment    TEXT,
+    nfo        BLOB,
+    content    TEXT,
+    source     TEXT,
+    CHECK (
+        status IN (
+                   'on', 'hdd', 'hdd_e', 'catalogued',
+                   'deferred', 'ext', 'cloud', 'burnt', 'updated',
+                   'onhold', 'watch', 'hidden', 'duplicate', 'trash',
+                   'closed', 'request', '2cat', '2compare', 'neformat',
+                   'sf88', 'BATA', 'away', 'ready2burn', 'accurip',
+                   'replace', '2burn', 'remove', 'paid', 'free', 'ftp',
+                   'stream', 'ai'
+            )
+        )
+);
+
+CREATE INDEX IF NOT EXISTS idx_srrdb_date
+    ON srrdb_releases (date);
+
+CREATE INDEX IF NOT EXISTS idx_srrdb_group
+    ON srrdb_releases (group_name);
+
+CREATE INDEX IF NOT EXISTS idx_srrdb_status
+    ON srrdb_releases (status);