fix: emit missing DFA_UNROLLED helpers in APT matchers

[jbachorik]

What does this PR do?

Fixes two places where annotation-processor (APT) matchers on the DFA_UNROLLED* path call a member the processor never generates. In both cases RuntimeCompiler already emits the member, so Reggie.compile works and only APT matchers fail.

• Missing findMatchFromForMatch: tagged-DFA match() calls the private findMatchFromForMatch helper, which the processor never emitted, so match() threw NoSuchMethodError. Repro: (?i)^https?://. The processor now calls generateFindMatchFromMethodTaggedNoCut. That method now returns early unless useTaggedDFA && groupCount > 0, the only case in which match() calls the helper.
• Missing lookup tables: the processor never called generateLookupTables, so charsets with 100+ ranges (e.g. .*[\p{IsAlphabetic}].*) threw NoSuchFieldError: $cs_0. The call now comes after every generate*Method.

Also adds two blank lines to AGENTS.md, written by the SessionStart hook.

Motivation

APT-generated matchers threw at runtime for patterns that work with Reggie.compile. This is the same dual-path gap as #136.

Related Issue(s)

Same class of bug as #136.

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactoring (no functional change)
• Documentation
• Test improvement
• Build/CI change

Checklist

• I have read the CONTRIBUTING.md guidelines
• All existing tests pass (./gradlew build)
• I have added tests for my changes
• I have updated documentation (if applicable)
• My commits are signed

Performance Impact

None. The change only adds members that were missing from generated classes.

Additional Notes

• Verified with ./gradlew :reggie-processor:test :reggie-runtime:test :reggie-codegen:test. The full ./gradlew build has not been run.
• Checked DFA_SWITCH and DFA_TABLE for the same gap; none found. Their private helpers (matchesAtStart, findMatchEnd, $nb_step_N, $fe_step_N) are emitted by the methods that call them, and DFA_TABLE decoders are runtime static methods.
• New tests in ReggieMatcherBytecodeGeneratorTest: taggedDfaUnrolledMatchHelperIsGenerated and dfaUnrolledLookupTablesAreGenerated.

🤖 Generated with Claude Code

[chatgpt-codex-connector]

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-05T12:52:37.387321Z	aecc3c4	Draft marked ready

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[datadog-prod-us1-3]

More details

The APT generator now emits both DFA_UNROLLED dependencies under the same conditions as their callers, matching the runtime compilation path.

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 85.1%. Comparing base (2ad23b7) to head (aecc3c4).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
.../codegen/codegen/DFAUnrolledBytecodeGenerator.java	50.0%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##              main    #147     +/-   ##
=========================================
+ Coverage     84.9%   85.1%   +0.2%     
  Complexity       1       1             
=========================================
  Files          163     163             
  Lines        49002   48870    -132     
  Branches      7009    6970     -39     
=========================================
+ Hits         41613   41614      +1     
+ Misses        5379    5255    -124     
+ Partials      2010    2001      -9     

Files with missing lines	Coverage Δ
...ggie/processor/ReggieMatcherBytecodeGenerator.java	74.7% <100.0%> (+0.4%)	⬆️
.../codegen/codegen/DFAUnrolledBytecodeGenerator.java	95.5% <50.0%> (+5.2%)	⬆️

... and 5 files with indirect coverage changes

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