fix(introspect): Harden live database connections and warn on malformed MySQL enum definitions

[mhiro2]

Summary

• Enforce TLS on remote TCP connections and apply a 30-second statement deadline for PostgreSQL,
  MySQL, and MariaDB introspection, while preserving local/loopback behavior untouched
• Extract shared ParallelCatalogReader trait and connection helpers to eliminate duplicated
  catalog assembly and pool cleanup across PostgreSQL, MySQL, and SQLite adapters
• Replace silent fallback on malformed MySQL ENUM/SET definitions with structured parse
  errors and emit diagnostics instead of silently ignoring bad input
• Update ARCHITECTURE.md, docs/cli-reference.md, and docs/getting-started.md to document
  the new security defaults

Changes

• dcf78ff : fix(introspect): harden live database connections
  • Enforce TLS on remote PostgreSQL, MySQL, and MariaDB TCP connections while keeping local/loopback and socket transports untouched
  • Apply a default 30-second statement deadline via PostgreSQL statement_timeout and MySQL/MariaDB max_execution_time/max_statement_time
  • Extract shared ParallelCatalogReader trait and close_pool_when_done helper to unify parallel catalog fetching and guaranteed pool draining across all three adapters
• 8174cde : fix(parser): warn on malformed mysql enum definitions
  • Replace silent None returns in MySQL ENUM/SET parsing with structured MySqlEnumLikeParseError variants covering incomplete escapes, unterminated quotes, missing parentheses, and unexpected separators
  • Emit parse diagnostics when malformed definitions are encountered instead of silently skipping them
  • Add unit tests for incomplete escape sequences and diagnostic emission on malformed definitions

[github-actions]

Code Metrics Report

	main (5dfe5d4)	#45 (730f4fb)	+/-
Coverage	94.0%	94.1%	+0.1%
Test Execution Time	1m39s	1m41s	+2s

Details

  |                     | main (5dfe5d4) | #45 (730f4fb) |  +/-  |
  |---------------------|----------------|---------------|-------|
+ | Coverage            |          94.0% |         94.1% | +0.1% |
  |   Files             |             71 |            73 |    +2 |
  |   Lines             |          29573 |         29749 |  +176 |
+ |   Covered           |          27805 |         28004 |  +199 |
- | Test Execution Time |          1m39s |         1m41s |   +2s |

Code coverage of files in pull request scope (88.0% → 89.3%)

Files	Coverage	+/-	Status
crates/relune-introspect/src/catalog.rs	97.1%	+97.1%	added
crates/relune-introspect/src/connect.rs	95.9%	+95.9%	added
crates/relune-introspect/src/lib.rs	90.0%	0.0%	modified
crates/relune-introspect/src/mysql/catalog.rs	94.2%	-1.0%	modified
crates/relune-introspect/src/mysql/mod.rs	86.6%	-1.3%	modified
crates/relune-introspect/src/postgres/catalog.rs	96.7%	+11.7%	modified
crates/relune-introspect/src/postgres/mod.rs	75.0%	-6.9%	modified
crates/relune-introspect/src/sqlite/catalog.rs	97.1%	0.0%	modified
crates/relune-introspect/src/sqlite/mod.rs	84.6%	-1.1%	modified
crates/relune-parser-sql/src/lib.rs	86.7%	+0.3%	modified

---

Reported by octocov