fix: resolve plugin system tech debt across 6 areas

[datlechin]

Summary

• Team ID placeholder: replaced "YOURTEAMID" with actual team ID D7HJ5TFYCU so sideloaded plugin signature verification works
• Bundle.unload() unreliable: added needsRestart flag and restart recommendation banner in Settings > Plugins after uninstalling a plugin
• No hot-reload notification: added pluginStateDidChange notification posted when plugins are enabled/disabled, so other parts of the app can react
• executeParameterized unsafe: rewrote default implementation with single-pass parser that skips ? inside quoted strings and escapes backslashes
• No dependency resolution: added dependencies: [String] to TableProPlugin protocol (default []) with load-time validation that logs warnings for missing/disabled dependencies
• Capabilities not enforced: registration now gated on declared capabilities with bidirectional mismatch warnings (plugin declares capability but doesn't conform, or conforms but doesn't declare)

Test plan

• Verify existing plugins still load and register correctly (all 8 drivers + 5 exporters)
• Toggle a plugin off/on in Settings > Plugins — confirm pluginStateDidChange fires
• Uninstall a user plugin — confirm restart banner appears
• Check Console.app for capability validation warnings (should be none for built-in plugins)
• Run swiftlint lint --strict on changed files — 0 violations