Future: more visualization styles and accessibility presets

[mrfloris]

Evaluate additional marker styles, color-blind-friendly presets, size and contrast controls, optional directional or distance cues, and more accessible label treatments after the first build has been tested on real worlds.

[mrfloris]

Beta 2 settings and options are implemented locally:

• Added Scanning, Markers, HUD, and Profiles pages plus an RGB color picker.
• Added current-chunk, nearby 3x3, and nearby 5x5 area presets; current-Y, nearby-height, and full-height scanning; automatic, debounced block-update, and manual refresh modes.
• Added independently bounded block and millisecond scan budgets, discovery and visible marker limits, render distance, and distance fade.
• Added distinct source, flowing, and waterlogged shapes, a persisted custom palette, and default, color-blind-safe, high-contrast, and monochrome presets.
• Added HUD anchor, offsets, scale, background opacity, compact mode, and an opt-in temporary hold key.
• Added local accessibility, exploration, and low-performance profiles.
• Added explicit configuration v1 to v2 migration plus validated local import/export in the normal config directory.
• Documented the stable concepts and the isolated exact-26.2 client block-update hook in ADR 0004.

Verification: a clean warning-enabled Gradle build passes, all 37 tests pass with zero failures, packaged metadata contains only the new ClientLevel mixin, and diff whitespace validation is clean. This issue remains open for real in-client UI/accessibility and frame-time testing, plus any later directional-cue exploration.

[mrfloris]

Visualization and accessibility implementation pass is complete in the Beta 2 worktree.

Implemented:

• Waterlogged top-cap and cross cues.
• Flowing-water level treatment by marker height, surface gauge, both, or fixed shape.
• Nearest-marker HUD direction/distance/vertical offset and an optional world highlight.
• Current-chunk or full scan-area frames, with solid loaded chunks and dashed skipped/pending chunks. This uses a primitive immutable snapshot and never requests or retains chunks.
• Hollow-box, stripe, and dot patterns plus accessible/classic pattern shortcuts.
• Compact HUD counts for visible, discovered, skipped, and stale-snapshot state.
• Opt-in narrator messages for scan completion and discovery-limit loss.
• Opt-in diagnostics for elapsed scan time, actually inspected blocks, scan progress, discarded markers, visible markers, and emitted vertices.
• A dedicated Features settings page and profile integration.

Performance and lifecycle safeguards:

• Optional nearest search is off by default and refreshes at a bounded cadence.
• Optional scan-area storage is allocated only when the boundary feature is enabled.
• Render geometry is distance/frustum/section culled and capped at 200,000 vertices per frame, below the staged 4 MiB position/color vertex buffer.
• Scanner publication remains generation-safe and releases chunk references after each chunk.

Verification:

• Clean Java 25 compile and 47 tests passed with zero failures.
• Minecraft 26.2 Fabric development client reached the main menu with WaterSourceMod loaded and renderer initialization completed without a mod exception.
• In-world visual QA is still required before closing this issue or calling the feature beta-verified.