fix(validation): reject unaddressable dictionaries

[gargiulofrancesco]

Rejects compact dictionaries containing more than 65,536 tokens during validation, preventing dictionaries that cannot be addressed by the u16 token type from becoming trusted.

Adds regression coverage for the exact 65,536-token boundary and rejection above it, and documents the limit in the dictionary invariants and interchange format.

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[codspeed-hq]

Merging this PR will improve performance by 37.34%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 4 improved benchmarks
❌ 2 regressed benchmarks
✅ 26 untouched benchmarks
⏩ 2 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	WallTime	decompress_all[("l_comment", 16)]	14.8 ms	18.8 ms	-21.53%
❌	WallTime	decompress_all[("o_comment", 16)]	13.5 ms	16.3 ms	-17.25%
⚡	WallTime	decompress_all[12]	748.1 µs	380.2 µs	+96.78%
⚡	WallTime	decompress_all[16]	744.5 µs	395.7 µs	+88.16%
⚡	WallTime	decompress_all[("p_name", 12)]	1,126.6 µs	629.1 µs	+79.09%
⚡	WallTime	decompress_all[("p_name", 16)]	916.1 µs	587.9 µs	+55.83%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing fix/dictionary-token-limit (a4914ef) with develop (ef5ac03)}

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩