[Meta] Bring docs up to date with everything shipped since v2.0.4

[RichardAnderson]

What does this PR do?

Reviews every commit since the v2.0.4 release and updates the developer docs, CLI reference, config reference, and UI guide to match what actually shipped.

• Undocumented features documented — the site details sidebar ([Feat] Add site details sidebar controls #190/[Fix] Site details sidebar polish, WordPress auto-login guardrails, and tray/filter corrections #216), the direct-mode trailing-slash 301 ([Fix] 301 redirect for directory requests without a trailing slash #199), and the macOS certutil resolution fix ([Fix] Find Homebrew/MacPorts certutil under the daemon's stripped PATH #206) had no docs at all.
• Partial coverage completed — routing rules ([Feat] Per-site routing rules for nested front controllers and SPA deep links #202) gained their IPC surface, [route_rules] config table, and crate-level docs; service overrides ([Feat] Per-service configuration overrides #204) gained yerd-core/yerd-services/yerd-doctor coverage and the new ServiceOverrideInvalid finding; proxy domains ([Feat] Extra domains, subdomains and wildcards for whole-host proxies #205) gained the user-facing guide; FPM streaming ([Feat] Stream PHP-FPM responses as they are flushed #214) replaced the stale buffer-until-END_REQUEST description.
• Stale references corrected — config schema version was still documented as 18 (now 23), yerd-config's CURRENT_VERSION as 11, cross-platform.md still called NSS trust "planned", and gui.md referenced a component renamed three commits ago.
• Module maps refreshed — yerd-core, yerd-proxy, yerd-services, yerd-platform, and both binaries were missing modules added over the last three weeks.
• CLI reference completed — added the Routing rules group, php ini/php pool, and the previously undocumented service add/remove/set-autostart/set-site commands.

Docs-only; npm run build passes and every new cross-page anchor was verified against the generated HTML.

Related issues

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Type of change

• Documentation

Platforms tested

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Checklist

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