fix(histogram): bound exact-bin SQL growth

[gcko]

PR checklist

• Ensure you have added or ran the appropriate tests for your PR.
• DCO signed

What type of PR is this?

Bugfix

What this PR does / why we need it:

• Adds bounded-size exact histogram SQL for runtime-proven DuckDB integral and fixed-DECIMAL columns.
• Uses scaled HUGEINT arithmetic with mathematical negative floor division and explicit terminal-maximum ownership.
• Requires identical authoritative base/current physical types before compacting, so mixed or stale metadata falls back safely.
• Keeps the exact literal comparison ladder for floats, unknown adapters/types, and every precision or overflow risk.
• Emits best-effort strategy/bin-count/SQL-length telemetry without affecting successful runs.
• Preserves the existing unbounded num_bins contract across direct, saved, and MCP requests.

Which issue(s) this PR fixes:

Closes DRC-4232

Special notes for your reviewer:

• Stack position: 3 of 3 in the histogram stack.
• Base/parent: feature/drc-4216-legacy-histogram-restore-datetimestamp-rendering-for-saved
• Parent PR: fix(histogram): restore temporal execution and rendering #1543
• GitHub stack: https://github.com/DataRecce/recce/stacks/1545
• Focused histogram/adapter/MCP suite: 240 passed; focused API/check/run suite: 60 passed.
• Full Python suite: 2,008 passed, 5 skipped.
• Full frontend suite at the final stack head: 4,414 passed, 5 skipped.
• make test-tox passed dbt 1.6, 1.7, 1.8, 1.9, and latest.
• OSS production build, repository flake8, pinned formatting/lint hooks, and diff checks passed.
• Adversarial regressions cover 37-digit Decimal context safety plus mixed and stale physical column types.

Does this PR introduce a user-facing change?:

Yes.

Large DuckDB histogram requests now use compact exact bucketing SQL while preserving existing request compatibility and safe fallbacks.

[codecov]

Codecov Report

❌ Patch coverage is 95.55035% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
recce/adapter/histogram_bucketing.py	90.90%	11 Missing ⚠️
tests/tasks/test_histogram.py	97.31%	5 Missing ⚠️
recce/tasks/histogram.py	95.16%	3 Missing ⚠️

Files with missing lines	Coverage Δ
tests/adapter/test_histogram_bucketing.py	100.00% <100.00%> (ø)
tests/test_mcp_server.py	99.89% <100.00%> (+<0.01%)	⬆️
recce/tasks/histogram.py	91.29% <95.16%> (+0.32%)	⬆️
tests/tasks/test_histogram.py	98.77% <97.31%> (-0.90%)	⬇️
recce/adapter/histogram_bucketing.py	90.90% <90.90%> (ø)

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[kentwelcome]

LGTM