Reads metadata.db and copies the books into a library — from a zip uploaded on
the library settings page, or from a path with `litestar calibre-import`. The
source is never touched, and re-running only picks up what is new.
Also names the formats mimetypes does not know: a Calibre library is full of
MOBI and AZW3, and a null content type used to fail the book endpoint.
Adds a reader section covering the vendored tree, the $foliate alias and the
traps around it, and refreshes the stale stack line, oklch claim and rough
edges. Records why CSP is not enabled in TODO.md.
patrick