test: run plugin and UI-free app tests hostless in packages

[datlechin]

Why

• TableProTests compiled 482 plugin sources and the UI-free app areas, so a test of a parser paid for the whole app host and every plugin file.

Change

• Bundled plugin logic runs in 6 hostless test bundles (MySQL, PostgreSQL, Redis, SQLite, ClickHouse, formats). PluginKit-free plugin code lives in TableProMySQLCore, TableProPostgreSQLCore and TableProRedisCore.
• Utilities, Autocomplete, SSH config and the MCP protocol core move into a new Packages/TableProMacCore, tested hostless in the Unit plan. iOS never links it.
• TableProTests compiles no file under Plugins/. No plugin links the package's PluginKit (checked with nm on every bundled plugin).

Verified

• Unit plan: 24,303 passed, 0 failures, across 14 targets. TableProCore swift test: 2,421 passed. Each Stage 2 test id is traced to where it runs now or to a named deletion. PluginKit ABI unchanged.

Not in this PR

• Test hygiene (waits, isolation, helpers), the parallel flip and the agent docs follow in the next PRs.