v4.6.2

Three fixes closing out the latent-bug backlog. The wire-protocol one is the
significant find:

• Fix (wire-protocol correctness, pre-existing): the PostgreSQL catalog
  dispatch matched pg_type / pg_tables / pg_views / pg_settings /
  pg_indexes / information_schema. as bare substrings of the raw statement
  text, so a statement that merely mentioned one — inside a string literal,
  a SQL comment, or as part of a longer identifier — had its real semantics
  discarded and a canned catalog response returned instead. Worst case, an
  UPDATE ... SET note='see pg_tables' silently never executed while the
  client received a reply it could not distinguish from success; a
  CREATE TABLE pg_type_registry (...) silently created nothing; and a user
  table named app_pg_settings was permanently shadowed. Interception is now
  restricted to read statements, matched against a literal- and
  comment-stripped view of the query, with word-boundary-aware marker
  matching. Client introspection (psql \dt, SQLAlchemy/pgAdmin/DBeaver/
  Drizzle probes) is unaffected.
• SIMILAR TO now matches PostgreSQL semantics. Three bugs fixed:
  alternation was not bound by the implicit full-string anchoring (so
  'zzxyz' SIMILAR TO 'abc|xyz' wrongly returned true); the repetition
  quantifiers * + ? {m,n} were treated as literal characters rather
  than metacharacters (so 'aaa' SIMILAR TO 'a+' wrongly returned false);
  and the ESCAPE clause was parsed but silently ignored. ESCAPE 'x',
  ESCAPE '' (escaping disabled), and the default backslash escape all
  behave per PostgreSQL now. This surface previously had no test coverage at
  all; it now has 10 tests.
• Fix: bulk loads persisted their row-id counter to a key the engine never
  reads back on open, leaving the canonical counter stale. It now writes
  through the canonical path — relevant for crash recovery of internal
  bookkeeping tables, which are skipped by the counter reseed added in 4.6.1.