[michalmedvecky]

Adds access to assigned registrations/surveys, consultation availability and own bookings, plus explicit booking/cancellation methods. It also fixes marks without a paper/event: udalostid=0 now reads the subject, teacher, date and value from the grade row instead of discarding it.

Changes:

• typed registration details/history, consultation blocks and server slot states; timezone-aware dates and no JavaScript evaluation;
• explicit writes with fresh availability/ownership checks, confirmation and read-back verification; dry_run only reads and uncertain writes are not retried;
• distinct grade_id for standalone marks (event_id=None), numeric event-ID normalization, and received/parsed/skipped reports without logging grade values.

Related to #135: this includes the numeric-ID normalization, but also retains standalone marks. Missing metadata for a nonzero event reference raises explicitly rather than silently dropping a mark from averages.

Tests: the complete suite passes using the repository's python -m unittest discover -s tests -v (84 tests). Pytest also passes: 84 tests plus 45 subtests. Booking tests use unittest, matching the existing suite and CI; fixtures contain synthetic/anonymized data, not account payloads.

Development and automated testing were carried out by coding agents, with iterative live-account feedback from me. I am successfully using these modules through Home Assistant OS 2026.10.1 with two child entries: consultation reads, child/teacher filtering, standalone marks and dry runs work; an existing real booking survived upgrades. Actual cancellation and an open registration/survey are not yet live-validated (the school currently has none open). This is validation at one school, not a claim of compatibility with all EduPage deployments.