Fix: Remove bucket linking to avoid regression in "Precise Forestry" preset

[bloom256]

Overview

This PR removes the recently introduced bucket linking optimization.

While bucket linking provided a modest speedup (~5%) for small sliding windows, it introduces a linear linking pass over all indoor buckets and only works for integer indoor/outdoor bucket ratios. For presets with very large sliding windows (notably "Precise Forestry", 10 km), this leads to a performance regression as bucket maps become large and linking cost dominates.

To avoid preset-dependent behavior and reduce code complexity, bucket linking is removed entirely in favor of the simpler hash-based lookup path.

Related issue: #339

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Changes

• Removed bucket linking logic (coarser_bucket and related helpers)
• Removed pointer-based outdoor bucket access
• Restored hash-map lookup for outdoor buckets in all cases
• Added a few small UTL profiler markers to make this code path easier to analyze

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Impact

• Fixes performance regression in "Precise Forestry"
• Simplifies code and removes fragile special-case logic
• Accepts ~5% slowdown for small-window presets in exchange for stable behavior across all configurations

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Notes

Bucket linking was designed for typical small sliding windows but does not scale to large-window presets and adds complexity for a relatively small gain. Removing it avoids future regressions and keeps behavior consistent across presets.