Expand Haven zoom while preserving road surface detail

[Guffawaffle]

Haven's native zoom-out range makes it difficult to see larger layouts. Extend the camera's fresh output along its existing direction while preserving native input, panning and close-range selection. A small depth bias on the known Haven asphalt materials keeps road surface detail visible across the expanded range.

• [graphics].haven_zoom sets the maximum camera distance: default 4000.0, or 0.0 for native behavior.
• [patches].havenzoomhooks independently controls hook installation and defaults to true; it is separate from the ordinary zoomhooks switch.

Validation: Windows mods and release DLL builds, English example TOML parsing, and git diff --check passed. The camera and road implementation passed Windows player testing at 6000 with full-out panning, roads, close-range selection and leave/reopen. The extracted artifact and independent switch combinations still need runtime smoke; Mac ARM64/Intel builds, exact-client native hook fit and player smoke remain pending.