…890)

## Description

Two bugs in `CodeStructureHandler`'s tree-sitter path. (1) Container
nodes (class/impl/trait/decorated definitions) were marked structural
over their full span and `_spans_to_mask` never un-marks, so every
method body inside a class was preserved and compression silently
no-opped at confidence 0.95. (2) Discovered while testing:
`tree-sitter-language-pack >= 1.0` switched to a Rust binding (methods,
not attributes; `parse(str)`), so the handler raised `TypeError` on
every call and silently fell back to regex.

Closes # <!-- compression-handler review -->

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- `headroom/compression/handlers/code_handler.py`: containers emit a
signature-only span (start to body start); recursion gives nested
functions their own signature/body split; decorated definitions emit no
whole-node span.
- `headroom/compression/handlers/code_handler.py`: small compat shim
supporting both the classic attribute API and the new Rust-binding
method API.
- `tests/test_compression/test_code_handler.py`: new file (the handler
had zero dedicated tests) covering class/decorated/impl body
compressibility, regex fallback, and a preservation-ratio bound.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ pytest tests/test_compression/ -q
92 passed, 8 skipped
```

## Real Behavior Proof

- Environment: local macOS, Python 3.11, tree-sitter-language-pack 1.8.1
installed, branch `fix/code-container-bodies`.
- Exact command / steps: `pytest tests/test_compression/ -q`.
- Observed result: Class method bodies are now compressible
(preservation ratio drops from ~1.0 to roughly the signature fraction);
the tree-sitter path runs instead of falling back to regex.
- Not tested: End-to-end through the live proxy pipeline.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Screenshots (if applicable)

N/A — library change. See Test Output.

## Additional Notes

PR 3 of 7; branched fresh from main (independent of #887/#889).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

## Description

Mechanical cleanups flagged in the review, no behaviour changes. Final
PR of the 7-PR series; merges both the json and code chains.

Closes # <!-- compression-handler review -->

## Type of Change

- [ ] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [x] Code refactoring (no functional changes)

## Changes Made

- `headroom/compression/handlers/json_handler.py`: remove a dead no-op
(`list(content) if tokens == list(content) else tokens` returned
`tokens` in both branches); clamp the string-escape scan so a trailing
backslash at EOF can't overrun.
- `headroom/compression/handlers/code_handler.py`: remove the unused
`CodeLanguage` enum and its import; slice-assign in `_spans_to_mask`
instead of a per-char loop; hoist `_detect_language` markers to a module
constant.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [ ] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ pytest tests/test_compression/ -q
111 passed, 8 skipped
```

## Real Behavior Proof

- Environment: local macOS, Python 3.11, tree-sitter-language-pack
1.8.1, branch `chore/handler-cleanups` (merges both chains).
- Exact command / steps: `pytest tests/test_compression/ -q`.
- Observed result: Full compression suite passes (111) with no behaviour
change; dead code removed and the escape scan no longer risks
overrunning the buffer.
- Not tested: No new behaviour to test — cleanups only, covered by the
existing suite.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Screenshots (if applicable)

N/A — cleanup only. See Test Output.

## Additional Notes

Depends on all of #887/#889/#890/#892/#893/#895 — review the top commit.
PR 7 of 7.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

🤖 I have created a release *beep* *boop*
---


<details><summary>0.26.0</summary>

##
[0.26.0](v0.25.0...v0.26.0)
(2026-06-16)


### Features

* add Copilot BYOK provider wrapper utilities and CLI support
([#1041](#1041))
([e67ee2a](e67ee2a))
* add dashboard agent usage stats
([#814](#814))
([6d3f39f](6d3f39f))
* Add support for Mistral Vibe CLI
([#935](#935))
([0932b8b](0932b8b))
* attribute reread waste to over-compression via marker check
([#901](#901))
([f928576](f928576))
* **bedrock:** cross-region + Converse compression; bundle proxy binary
in images ([#999](#999))
([0dc2e1c](0dc2e1c))
* **dashboard:** surface compression-vs-cache net impact in Prefix Cache
panel ([#913](#913))
([2a4d300](2a4d300))
* **evals:** adversarial-input robustness grid for compressors
([#918](#918))
([5939004](5939004))
* **parser:** detect re-issued identical tool calls as reread waste
([#909](#909))
([7d4ae86](7d4ae86))
* **policy:** batch deep edits through one cache-bust
([#856](#856) P3a)
([#1015](#1015))
([c2e52fe](c2e52fe))
* **policy:** consume net-cost mutation gate in ContentRouter
([#856](#856) P2)
([#905](#905))
([553ade4](553ade4))
* **proxy:** compress AWS Bedrock InvokeModel requests via configurable
upstream ([#720](#720))
([7edb27a](7edb27a))


### Bug Fixes

* **anthropic:** strip styled Claude model ids
([#651](#651))
([0c5c89d](0c5c89d))
* **anyllm:** forward openai api_base/api_key to the any-llm backend
([#942](#942))
([#954](#954))
([a7ee8a6](a7ee8a6))
* **cache:** guard None exemplar embeddings in dynamic detector
([#950](#950))
([1ec9320](1ec9320))
* **cache:** name the missing piece in semantic detector guard
([#1018](#1018))
([3b0bcee](3b0bcee))
* **ci:** check out repo in PR Governance label job
([#1021](#1021))
([4558bc2](4558bc2))
* **ci:** make PR governance advisory
([#1047](#1047))
([74dff94](74dff94))
* **codex:** compute waste signals on the OpenAI Responses path
([#898](#898))
([b9e2761](b9e2761))
* **codex:** poll /wham/usage for subscription limits (handshake no
longer sends x-codex-* headers)
([#924](#924))
([8c00f71](8c00f71))
* **codex:** PR health label check state
([#986](#986))
([99c874d](99c874d))
* **codex:** retag thread providers so history menu stays whole across
the proxy boundary
([#1034](#1034))
([74ae781](74ae781))
* **codex:** write canonical hooks feature flag and migrate deprecated
codex_hooks ([#743](#743))
([dff6a19](dff6a19))
* **compression:** convert tree-sitter byte offsets to char offsets
([#892](#892))
([b1f700f](b1f700f))
* **compression:** correct JSON array item counting and entropy gate
([#887](#887))
([d6f0f0f](d6f0f0f))
* **compression:** keep container bodies compressible in code handler
([#890](#890))
([16ed73b](16ed73b))
* **compression:** measure short-value threshold on payload, not token
([#889](#889))
([65b0e8c](65b0e8c))
* **compression:** use thread-local tree-sitter parsers in code handler
([#893](#893))
([6cdb846](6cdb846))
* **gemini:** surface functionResponse payloads to waste-signal
detection ([#897](#897))
([9b0c840](9b0c840))
* **learn:** decode directory names with spaces in Windows project paths
([#997](#997))
([#1027](#1027))
([2d3701b](2d3701b))
* **learn:** scan subagent and workflow transcripts
([#1045](#1045))
([0ddd4ed](0ddd4ed))
* **openclaw:** declare headroom_retrieve tool contract
([#947](#947))
([7c8c909](7c8c909))
* **policy:** correct warm-cache penalty in net_mutation_gain to (S +
dT) ([#903](#903))
([0632eba](0632eba))
* **proxy:** add native Bedrock converse-stream route
([#917](#917))
([b08ec15](b08ec15))
* **proxy:** keep codex image-generation WS turns alive through the
relay ([#1000](#1000))
([7dbbb40](7dbbb40))
* **proxy:** make budget enforcement actually work
([#885](#885))
([a14ab45](a14ab45))
* **proxy:** read RTK gain stats globally by default
([#957](#957))
([b70fccb](b70fccb))
* route v1internal code assist requests to cloudcode-pa.googleapis…
([#821](#821))
([e20f16b](e20f16b))
* **serena:** stop the Serena dashboard popup and make --no-serena
actually disable Serena
([#1003](#1003))
([919379a](919379a))
* support Copilot Business subscription auth
([#641](#641))
([0b4a4bd](0b4a4bd))
* wire HEADROOM_EXCLUDE_TOOLS / HEADROOM_TOOL_PROFILES into Click proxy
entrypoint ([#943](#943))
([9b7b436](9b7b436))
* **wrap:** avoid duplicate top-level keys when injecting codex provider
([#884](#884))
([dd22cfd](dd22cfd))


### Code Refactoring

* DRY cache logic, add thread safety, fix Bash exclusion
([#704](#704))
([e36fccd](e36fccd))
</details>

---
This PR was generated with [Release
Please](https://github.com/googleapis/release-please). See
[documentation](https://github.com/googleapis/release-please#release-please).

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

…headroomlabs-ai#889)

## Description

`JSONStructureHandler._should_preserve_token` compared `len(token.text)`
— which includes both quote characters — against
`short_value_threshold`. A value of exactly threshold length was
rejected: the documented "20-char threshold" was effectively 18 chars of
payload. Stacked on headroomlabs-ai#887.

Closes # <!-- compression-handler review -->

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- `headroom/compression/handlers/json_handler.py`: strip quotes once at
the top of the string-value branch and use the payload length for both
the short-value and entropy checks.
- `tests/test_compression/test_json_handler.py`: regression test for a
value of exactly `short_value_threshold` length.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ pytest tests/test_compression/test_json_handler.py -q
33 passed
```

## Real Behavior Proof

- Environment: local macOS, Python 3.11, branch
`fix/json-quote-threshold` (stacked on headroomlabs-ai#887).
- Exact command / steps: `pytest
tests/test_compression/test_json_handler.py -q`.
- Observed result: A 20-char value is preserved at a 20-char threshold;
previously it was dropped due to the +2 quote miscount.
- Not tested: End-to-end through the live proxy pipeline.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Screenshots (if applicable)

N/A — library change. See Test Output.

## Additional Notes

Stacked on headroomlabs-ai#887 — review the top commit until that merges. PR 2 of 7.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

## Description

Mechanical cleanups flagged in the review, no behaviour changes. Final
PR of the 7-PR series; merges both the json and code chains.

Closes # <!-- compression-handler review -->

## Type of Change

- [ ] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [x] Code refactoring (no functional changes)

## Changes Made

- `headroom/compression/handlers/json_handler.py`: remove a dead no-op
(`list(content) if tokens == list(content) else tokens` returned
`tokens` in both branches); clamp the string-escape scan so a trailing
backslash at EOF can't overrun.
- `headroom/compression/handlers/code_handler.py`: remove the unused
`CodeLanguage` enum and its import; slice-assign in `_spans_to_mask`
instead of a per-char loop; hoist `_detect_language` markers to a module
constant.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [x] Type checking passes (`mypy headroom`)
- [ ] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ pytest tests/test_compression/ -q
111 passed, 8 skipped
```

## Real Behavior Proof

- Environment: local macOS, Python 3.11, tree-sitter-language-pack
1.8.1, branch `chore/handler-cleanups` (merges both chains).
- Exact command / steps: `pytest tests/test_compression/ -q`.
- Observed result: Full compression suite passes (111) with no behaviour
change; dead code removed and the escape scan no longer risks
overrunning the buffer.
- Not tested: No new behaviour to test — cleanups only, covered by the
existing suite.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] I have updated the CHANGELOG.md if applicable

## Screenshots (if applicable)

N/A — cleanup only. See Test Output.

## Additional Notes

Depends on all of headroomlabs-ai#887/headroomlabs-ai#889/headroomlabs-ai#890/headroomlabs-ai#892/headroomlabs-ai#893/headroomlabs-ai#895 — review the top commit.
PR 7 of 7.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

🤖 I have created a release *beep* *boop*
---


<details><summary>0.26.0</summary>

##
[0.26.0](headroomlabs-ai/headroom@v0.25.0...v0.26.0)
(2026-06-16)


### Features

* add Copilot BYOK provider wrapper utilities and CLI support
([headroomlabs-ai#1041](headroomlabs-ai#1041))
([e67ee2a](headroomlabs-ai@e67ee2a))
* add dashboard agent usage stats
([headroomlabs-ai#814](headroomlabs-ai#814))
([6d3f39f](headroomlabs-ai@6d3f39f))
* Add support for Mistral Vibe CLI
([headroomlabs-ai#935](headroomlabs-ai#935))
([0932b8b](headroomlabs-ai@0932b8b))
* attribute reread waste to over-compression via marker check
([headroomlabs-ai#901](headroomlabs-ai#901))
([f928576](headroomlabs-ai@f928576))
* **bedrock:** cross-region + Converse compression; bundle proxy binary
in images ([headroomlabs-ai#999](headroomlabs-ai#999))
([0dc2e1c](headroomlabs-ai@0dc2e1c))
* **dashboard:** surface compression-vs-cache net impact in Prefix Cache
panel ([headroomlabs-ai#913](headroomlabs-ai#913))
([2a4d300](headroomlabs-ai@2a4d300))
* **evals:** adversarial-input robustness grid for compressors
([headroomlabs-ai#918](headroomlabs-ai#918))
([5939004](headroomlabs-ai@5939004))
* **parser:** detect re-issued identical tool calls as reread waste
([headroomlabs-ai#909](headroomlabs-ai#909))
([7d4ae86](headroomlabs-ai@7d4ae86))
* **policy:** batch deep edits through one cache-bust
([headroomlabs-ai#856](headroomlabs-ai#856) P3a)
([headroomlabs-ai#1015](headroomlabs-ai#1015))
([c2e52fe](headroomlabs-ai@c2e52fe))
* **policy:** consume net-cost mutation gate in ContentRouter
([headroomlabs-ai#856](headroomlabs-ai#856) P2)
([headroomlabs-ai#905](headroomlabs-ai#905))
([553ade4](headroomlabs-ai@553ade4))
* **proxy:** compress AWS Bedrock InvokeModel requests via configurable
upstream ([headroomlabs-ai#720](headroomlabs-ai#720))
([7edb27a](headroomlabs-ai@7edb27a))


### Bug Fixes

* **anthropic:** strip styled Claude model ids
([headroomlabs-ai#651](headroomlabs-ai#651))
([0c5c89d](headroomlabs-ai@0c5c89d))
* **anyllm:** forward openai api_base/api_key to the any-llm backend
([headroomlabs-ai#942](headroomlabs-ai#942))
([headroomlabs-ai#954](headroomlabs-ai#954))
([a7ee8a6](headroomlabs-ai@a7ee8a6))
* **cache:** guard None exemplar embeddings in dynamic detector
([headroomlabs-ai#950](headroomlabs-ai#950))
([1ec9320](headroomlabs-ai@1ec9320))
* **cache:** name the missing piece in semantic detector guard
([headroomlabs-ai#1018](headroomlabs-ai#1018))
([3b0bcee](headroomlabs-ai@3b0bcee))
* **ci:** check out repo in PR Governance label job
([headroomlabs-ai#1021](headroomlabs-ai#1021))
([4558bc2](headroomlabs-ai@4558bc2))
* **ci:** make PR governance advisory
([headroomlabs-ai#1047](headroomlabs-ai#1047))
([74dff94](headroomlabs-ai@74dff94))
* **codex:** compute waste signals on the OpenAI Responses path
([headroomlabs-ai#898](headroomlabs-ai#898))
([b9e2761](headroomlabs-ai@b9e2761))
* **codex:** poll /wham/usage for subscription limits (handshake no
longer sends x-codex-* headers)
([headroomlabs-ai#924](headroomlabs-ai#924))
([8c00f71](headroomlabs-ai@8c00f71))
* **codex:** PR health label check state
([headroomlabs-ai#986](headroomlabs-ai#986))
([99c874d](headroomlabs-ai@99c874d))
* **codex:** retag thread providers so history menu stays whole across
the proxy boundary
([headroomlabs-ai#1034](headroomlabs-ai#1034))
([74ae781](headroomlabs-ai@74ae781))
* **codex:** write canonical hooks feature flag and migrate deprecated
codex_hooks ([headroomlabs-ai#743](headroomlabs-ai#743))
([dff6a19](headroomlabs-ai@dff6a19))
* **compression:** convert tree-sitter byte offsets to char offsets
([headroomlabs-ai#892](headroomlabs-ai#892))
([b1f700f](headroomlabs-ai@b1f700f))
* **compression:** correct JSON array item counting and entropy gate
([headroomlabs-ai#887](headroomlabs-ai#887))
([d6f0f0f](headroomlabs-ai@d6f0f0f))
* **compression:** keep container bodies compressible in code handler
([headroomlabs-ai#890](headroomlabs-ai#890))
([16ed73b](headroomlabs-ai@16ed73b))
* **compression:** measure short-value threshold on payload, not token
([headroomlabs-ai#889](headroomlabs-ai#889))
([65b0e8c](headroomlabs-ai@65b0e8c))
* **compression:** use thread-local tree-sitter parsers in code handler
([headroomlabs-ai#893](headroomlabs-ai#893))
([6cdb846](headroomlabs-ai@6cdb846))
* **gemini:** surface functionResponse payloads to waste-signal
detection ([headroomlabs-ai#897](headroomlabs-ai#897))
([9b0c840](headroomlabs-ai@9b0c840))
* **learn:** decode directory names with spaces in Windows project paths
([headroomlabs-ai#997](headroomlabs-ai#997))
([headroomlabs-ai#1027](headroomlabs-ai#1027))
([2d3701b](headroomlabs-ai@2d3701b))
* **learn:** scan subagent and workflow transcripts
([headroomlabs-ai#1045](headroomlabs-ai#1045))
([0ddd4ed](headroomlabs-ai@0ddd4ed))
* **openclaw:** declare headroom_retrieve tool contract
([headroomlabs-ai#947](headroomlabs-ai#947))
([7c8c909](headroomlabs-ai@7c8c909))
* **policy:** correct warm-cache penalty in net_mutation_gain to (S +
dT) ([headroomlabs-ai#903](headroomlabs-ai#903))
([0632eba](headroomlabs-ai@0632eba))
* **proxy:** add native Bedrock converse-stream route
([headroomlabs-ai#917](headroomlabs-ai#917))
([b08ec15](headroomlabs-ai@b08ec15))
* **proxy:** keep codex image-generation WS turns alive through the
relay ([headroomlabs-ai#1000](headroomlabs-ai#1000))
([7dbbb40](headroomlabs-ai@7dbbb40))
* **proxy:** make budget enforcement actually work
([headroomlabs-ai#885](headroomlabs-ai#885))
([a14ab45](headroomlabs-ai@a14ab45))
* **proxy:** read RTK gain stats globally by default
([headroomlabs-ai#957](headroomlabs-ai#957))
([b70fccb](headroomlabs-ai@b70fccb))
* route v1internal code assist requests to cloudcode-pa.googleapis…
([headroomlabs-ai#821](headroomlabs-ai#821))
([e20f16b](headroomlabs-ai@e20f16b))
* **serena:** stop the Serena dashboard popup and make --no-serena
actually disable Serena
([headroomlabs-ai#1003](headroomlabs-ai#1003))
([919379a](headroomlabs-ai@919379a))
* support Copilot Business subscription auth
([headroomlabs-ai#641](headroomlabs-ai#641))
([0b4a4bd](headroomlabs-ai@0b4a4bd))
* wire HEADROOM_EXCLUDE_TOOLS / HEADROOM_TOOL_PROFILES into Click proxy
entrypoint ([headroomlabs-ai#943](headroomlabs-ai#943))
([9b7b436](headroomlabs-ai@9b7b436))
* **wrap:** avoid duplicate top-level keys when injecting codex provider
([headroomlabs-ai#884](headroomlabs-ai#884))
([dd22cfd](headroomlabs-ai@dd22cfd))


### Code Refactoring

* DRY cache logic, add thread safety, fix Bash exclusion
([headroomlabs-ai#704](headroomlabs-ai#704))
([e36fccd](headroomlabs-ai@e36fccd))
</details>

---
This PR was generated with [Release
Please](https://github.com/googleapis/release-please). See
[documentation](https://github.com/googleapis/release-please#release-please).

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>