Bound input field sizes against memory/DB/Qdrant bloat (DoS-by-self):
- content: 65536 bytes via mb_strlen
- tags: max 100 entries; each tag max 128 chars
- agent_id, type: 64 chars each
- project, org: 128 chars each
- supersedes_id: ULID-shape only
validateRememberInput() throws InvalidArgumentException at every entry
point (remember, recall, forget) before any DB or upstream call. Field-
specific error messages so callers know which field violated.
Pest covers good-path, content-too-long, tags-array-too-large, tag-
length, exact-boundary cases.
Co-authored-by: Codex <noreply@openai.com>
Closes tasks.lthn.sh/view.php?id=1001