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


<details><summary>0.29.0</summary>

##
[0.29.0](v0.28.0...v0.29.0)
(2026-07-03)


### Features

* **proxy:** add --lossless no-CCR mode with format-native compaction
([#1721](#1721))
([c75ebde](c75ebde))
* **stats:** surface Codex WS compression counters in /stats summary
([#1680](#1680))
([2fe19c3](2fe19c3))
* **transforms:** adaptive Otsu KEEP/DROP threshold (+ land relevance
split on main)
([#1726](#1726))
([eea667a](eea667a))


### Bug Fixes

* **bedrock:** fail fast when session-token auth lacks botocore
([#1553](#1553))
([54cfa36](54cfa36))
* **bedrock:** route ARNs via converse, named AWS profiles, and au. re…
([#1456](#1456))
([7d87aa2](7d87aa2))
* **ccr:** honor workspace dir for sqlite store
([#1564](#1564))
([96e1dfe](96e1dfe))
* **claude:** surface Remote Control proxy incompatibility
([#1610](#1610))
([4bf7f92](4bf7f92))
* **cli:** stop advertising unwired compression tuning env vars in
banner
([#1634](#1634))
([d5bf98d](d5bf98d))
* **codex:** avoid duplicate headroom provider config
([#1431](#1431))
([ddd4adf](ddd4adf))
* **compression:** reject lossy unmarked tool output in unit router path
([#1479](#1479))
([de24cd5](de24cd5))
* **cortex-code:** migrate to current Cortex REST API endpoints + add
e2e benchmarks
([#1474](#1474))
([f00ace6](f00ace6))
* **dashboard:** align token savings headline denominator
([#1653](#1653))
([646e705](646e705))
* **dashboard:** derive per-project setup URL from live origin
([#1511](#1511))
([e035aef](e035aef))
* **detection:** contain unidiff panic on orphaned +++ target line
([#1548](#1548))
([e386c09](e386c09))
* **evals:** CJK-aware F1 tokenization + token estimation
([#1527](#1527))
([99a8540](99a8540))
* **install:** close parent log fd in start_detached_agent
([#1576](#1576))
([816cb85](816cb85))
* **install:** use Windows-safe PID liveness probe in runtime_status
([#1544](#1544))
([#1560](#1560))
([6b227b9](6b227b9))
* **learn:** aggregate verbosity baselines across projects instead of
overwriting
([#1288](#1288))
([27a5468](27a5468))
* **mcp:** show lifetime totals and label rolling session scope in
headroom_stats
([#1428](#1428))
([1c0e152](1c0e152))
* **memory:** cap local embedder CPU thread oversubscription
([#198](#198))
([#1559](#1559))
([b84afbf](b84afbf))
* **memory:** singleflight LocalBackend init to stop cold-start races
([#1691](#1691))
([bec47a1](bec47a1))
* **openclaw:** detect uv-installed headroom binary in ~/.local/bin
([#1459](#1459))
([adaeb88](adaeb88))
* **opencode:** preserve custom OpenAI gateway paths
([#1596](#1596))
([c19347c](c19347c))
* **opencode:** route native providers + load transport plugin, fix
Serena context
([#1573](#1573))
([ad0034f](ad0034f))
* preserve anthropic passthrough tool order
([#1427](#1427))
([a932247](a932247))
* **proxy/auth:** match real Anthropic OAuth token prefix (sk-ant-oat)
([#1672](#1672))
([8cddf9b](8cddf9b))
* **proxy:** expose persistent savings metrics
([#1647](#1647))
([5fe4e7b](5fe4e7b))
* **proxy:** fail open when kompress saturation would exhaust
pre-upstream budget
([#1430](#1430))
([15ac650](15ac650))
* **proxy:** handle streaming CCR retrieval
([#1451](#1451))
([d337e3b](d337e3b))
* **proxy:** include system/tools/sampling in cache key
([#1473](#1473))
([312129a](312129a))
* **proxy:** preserve Responses passthrough bytes
([#1598](#1598))
([2a34a82](2a34a82))
* **proxy:** strip Codex lite header on the HTTP /responses path
([#1663](#1663))
([9fbd47b](9fbd47b))
* **proxy:** wire --compression-max-workers /
HEADROOM_COMPRESSION_MAX_WORKERS
([#1632](#1632))
([814ffa3](814ffa3))
* **savings:** count cache-read tokens in input cost estimate
([#1429](#1429))
([72ade37](72ade37))
* skip Magika backend on x86 CPUs without AVX2
([#1162](#1162))
([64783d8](64783d8))
* **transforms/content-router:** route grep/log output away from HTML
extractor
([#1719](#1719))
([0d18ef2](0d18ef2))
* **transforms:** bound native content detection with a Windows watchdog
([#575](#575))
([#1563](#1563))
([95abca3](95abca3))
* Vertex AI support for Claude Code with ANTHROPIC_VERTEX_BASE_URL
([#1393](#1393))
([cff7247](cff7247))
* **wrap:** detach the shared proxy on Windows so it survives an
ungraceful agent close
([#1464](#1464))
([6cba441](6cba441))
* **wrap:** preserve custom Vertex base URL
([#1477](#1477))
([75427bb](75427bb))
* **wrap:** remove rtk instructions from Codex AGENTS.md on unwrap
([#1604](#1604))
([c9d717c](c9d717c))
</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>

…adroomlabs-ai#1548)

## Description

`headroom._core.detect_content_type()` panics with
`pyo3_runtime.PanicException: called Option::unwrap() on a None value`
on any text containing a `+++ ` target line with no preceding `--- `
source line — e.g. `set -x` xtrace output or a partial `git diff` quoted
out of context.

The panic originates in the bundled `unidiff` 0.4.0 parser
(`lib.rs:665`): on a target-file header it does
`source_file.clone().unwrap()`, but `source_file` is still `None` when
no source header was seen. The crate's only guard there checks
`current_file`, not `source_file`, so it falls through and unwraps
`None` instead of returning `Err`.

Because detection runs inside a `ThreadPoolExecutor` worker on the
Python side, the native panic surfaces as an uncaught `PanicException`,
bypasses the compression error handling, and returns **HTTP 500** for
the whole request. The failure is deterministic on payload content, so
client retries fail until the offending text leaves the context window.

`is_diff()` in `unidiff_detector.rs` is the single entry point that
drives `PatchSet::parse`, so the fix is contained there: wrap the parse
in `catch_unwind` and treat an unparseable fragment as "not a diff".
This matches the workspace's deliberate no-`panic = "abort"` policy
(Cargo.toml) of surviving bad input rather than taking the long-lived
proxy down.

Closes headroomlabs-ai#1547

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)

## Changes Made

- `crates/headroom-core/src/transforms/unidiff_detector.rs`: contain any
`unidiff` parser panic inside `is_diff()` via `catch_unwind`, returning
`false` (not a diff) on panic. Added regression test
`orphaned_target_line_does_not_panic`.
- `CHANGELOG.md`: note under Unreleased → Fixed.

## Testing

- [x] Unit tests pass (`cargo test -p headroom-core`)
- [x] Linting passes (`cargo fmt --check`, `cargo clippy`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

Before the fix (regression test reproduces the exact panic):

```text
running 1 test
test transforms::unidiff_detector::tests::orphaned_target_line_does_not_panic ... FAILED

---- transforms::unidiff_detector::tests::orphaned_target_line_does_not_panic stdout ----
thread '...' panicked at unidiff-0.4.0/src/lib.rs:665:54:
called `Option::unwrap()` on a `None` value

test result: FAILED. 0 passed; 1 failed; ...
```

After the fix:

```text
running 15 tests
test transforms::unidiff_detector::tests::orphaned_target_line_does_not_panic ... ok
test transforms::unidiff_detector::tests::standard_git_diff_detected ... ok
...
test result: ok. 15 passed; 0 failed; 0 ignored

# whole transforms suite
test result: ok. 700 passed; 0 failed; 0 ignored
```

## Real Behavior Proof

- Environment: macOS (arm64), Rust stable, `cargo test -p
headroom-core`.
- Exact command / steps: `cargo test -p headroom-core --lib
unidiff_detector` then `cargo test -p headroom-core`. (1) Added a test
calling `is_diff("+++ x")` / `detect_diff("+++ x")` and ran it →
reproduced the panic at `unidiff-0.4.0/src/lib.rs:665:54` (output
above), confirming the same crash path as the report. (2) Applied the
`catch_unwind` containment in `is_diff()`. (3) Re-ran the test and the
full transforms suite → all green (output above).
- Observed result: the orphaned-`+++ ` input is now classified as "not a
diff" (plain text) and returns normally instead of panicking. Real diffs
(`standard_git_diff_detected`, `naked_hunk_without_git_header_detected`,
multi-file, added/removed-only) still detect correctly, so the
containment does not weaken detection.
- Not tested: I exercised the Rust layer directly (the sole `unidiff`
caller, which the `headroom._core.detect_content_type` binding routes
through) rather than rebuilding the Python wheel; I did not run the live
proxy against a real provider.

## 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
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective
- [x] New and existing unit tests pass locally with my changes
- [x] I have updated the CHANGELOG.md

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


<details><summary>0.29.0</summary>

##
[0.29.0](headroomlabs-ai/headroom@v0.28.0...v0.29.0)
(2026-07-03)


### Features

* **proxy:** add --lossless no-CCR mode with format-native compaction
([headroomlabs-ai#1721](headroomlabs-ai#1721))
([c75ebde](headroomlabs-ai@c75ebde))
* **stats:** surface Codex WS compression counters in /stats summary
([headroomlabs-ai#1680](headroomlabs-ai#1680))
([2fe19c3](headroomlabs-ai@2fe19c3))
* **transforms:** adaptive Otsu KEEP/DROP threshold (+ land relevance
split on main)
([headroomlabs-ai#1726](headroomlabs-ai#1726))
([eea667a](headroomlabs-ai@eea667a))


### Bug Fixes

* **bedrock:** fail fast when session-token auth lacks botocore
([headroomlabs-ai#1553](headroomlabs-ai#1553))
([54cfa36](headroomlabs-ai@54cfa36))
* **bedrock:** route ARNs via converse, named AWS profiles, and au. re…
([headroomlabs-ai#1456](headroomlabs-ai#1456))
([7d87aa2](headroomlabs-ai@7d87aa2))
* **ccr:** honor workspace dir for sqlite store
([headroomlabs-ai#1564](headroomlabs-ai#1564))
([96e1dfe](headroomlabs-ai@96e1dfe))
* **claude:** surface Remote Control proxy incompatibility
([headroomlabs-ai#1610](headroomlabs-ai#1610))
([4bf7f92](headroomlabs-ai@4bf7f92))
* **cli:** stop advertising unwired compression tuning env vars in
banner
([headroomlabs-ai#1634](headroomlabs-ai#1634))
([d5bf98d](headroomlabs-ai@d5bf98d))
* **codex:** avoid duplicate headroom provider config
([headroomlabs-ai#1431](headroomlabs-ai#1431))
([ddd4adf](headroomlabs-ai@ddd4adf))
* **compression:** reject lossy unmarked tool output in unit router path
([headroomlabs-ai#1479](headroomlabs-ai#1479))
([de24cd5](headroomlabs-ai@de24cd5))
* **cortex-code:** migrate to current Cortex REST API endpoints + add
e2e benchmarks
([headroomlabs-ai#1474](headroomlabs-ai#1474))
([f00ace6](headroomlabs-ai@f00ace6))
* **dashboard:** align token savings headline denominator
([headroomlabs-ai#1653](headroomlabs-ai#1653))
([646e705](headroomlabs-ai@646e705))
* **dashboard:** derive per-project setup URL from live origin
([headroomlabs-ai#1511](headroomlabs-ai#1511))
([e035aef](headroomlabs-ai@e035aef))
* **detection:** contain unidiff panic on orphaned +++ target line
([headroomlabs-ai#1548](headroomlabs-ai#1548))
([e386c09](headroomlabs-ai@e386c09))
* **evals:** CJK-aware F1 tokenization + token estimation
([headroomlabs-ai#1527](headroomlabs-ai#1527))
([99a8540](headroomlabs-ai@99a8540))
* **install:** close parent log fd in start_detached_agent
([headroomlabs-ai#1576](headroomlabs-ai#1576))
([816cb85](headroomlabs-ai@816cb85))
* **install:** use Windows-safe PID liveness probe in runtime_status
([headroomlabs-ai#1544](headroomlabs-ai#1544))
([headroomlabs-ai#1560](headroomlabs-ai#1560))
([6b227b9](headroomlabs-ai@6b227b9))
* **learn:** aggregate verbosity baselines across projects instead of
overwriting
([headroomlabs-ai#1288](headroomlabs-ai#1288))
([27a5468](headroomlabs-ai@27a5468))
* **mcp:** show lifetime totals and label rolling session scope in
headroom_stats
([headroomlabs-ai#1428](headroomlabs-ai#1428))
([1c0e152](headroomlabs-ai@1c0e152))
* **memory:** cap local embedder CPU thread oversubscription
([headroomlabs-ai#198](headroomlabs-ai#198))
([headroomlabs-ai#1559](headroomlabs-ai#1559))
([b84afbf](headroomlabs-ai@b84afbf))
* **memory:** singleflight LocalBackend init to stop cold-start races
([headroomlabs-ai#1691](headroomlabs-ai#1691))
([bec47a1](headroomlabs-ai@bec47a1))
* **openclaw:** detect uv-installed headroom binary in ~/.local/bin
([headroomlabs-ai#1459](headroomlabs-ai#1459))
([adaeb88](headroomlabs-ai@adaeb88))
* **opencode:** preserve custom OpenAI gateway paths
([headroomlabs-ai#1596](headroomlabs-ai#1596))
([c19347c](headroomlabs-ai@c19347c))
* **opencode:** route native providers + load transport plugin, fix
Serena context
([headroomlabs-ai#1573](headroomlabs-ai#1573))
([ad0034f](headroomlabs-ai@ad0034f))
* preserve anthropic passthrough tool order
([headroomlabs-ai#1427](headroomlabs-ai#1427))
([a932247](headroomlabs-ai@a932247))
* **proxy/auth:** match real Anthropic OAuth token prefix (sk-ant-oat)
([headroomlabs-ai#1672](headroomlabs-ai#1672))
([8cddf9b](headroomlabs-ai@8cddf9b))
* **proxy:** expose persistent savings metrics
([headroomlabs-ai#1647](headroomlabs-ai#1647))
([5fe4e7b](headroomlabs-ai@5fe4e7b))
* **proxy:** fail open when kompress saturation would exhaust
pre-upstream budget
([headroomlabs-ai#1430](headroomlabs-ai#1430))
([15ac650](headroomlabs-ai@15ac650))
* **proxy:** handle streaming CCR retrieval
([headroomlabs-ai#1451](headroomlabs-ai#1451))
([d337e3b](headroomlabs-ai@d337e3b))
* **proxy:** include system/tools/sampling in cache key
([headroomlabs-ai#1473](headroomlabs-ai#1473))
([312129a](headroomlabs-ai@312129a))
* **proxy:** preserve Responses passthrough bytes
([headroomlabs-ai#1598](headroomlabs-ai#1598))
([2a34a82](headroomlabs-ai@2a34a82))
* **proxy:** strip Codex lite header on the HTTP /responses path
([headroomlabs-ai#1663](headroomlabs-ai#1663))
([9fbd47b](headroomlabs-ai@9fbd47b))
* **proxy:** wire --compression-max-workers /
HEADROOM_COMPRESSION_MAX_WORKERS
([headroomlabs-ai#1632](headroomlabs-ai#1632))
([814ffa3](headroomlabs-ai@814ffa3))
* **savings:** count cache-read tokens in input cost estimate
([headroomlabs-ai#1429](headroomlabs-ai#1429))
([72ade37](headroomlabs-ai@72ade37))
* skip Magika backend on x86 CPUs without AVX2
([headroomlabs-ai#1162](headroomlabs-ai#1162))
([64783d8](headroomlabs-ai@64783d8))
* **transforms/content-router:** route grep/log output away from HTML
extractor
([headroomlabs-ai#1719](headroomlabs-ai#1719))
([0d18ef2](headroomlabs-ai@0d18ef2))
* **transforms:** bound native content detection with a Windows watchdog
([headroomlabs-ai#575](headroomlabs-ai#575))
([headroomlabs-ai#1563](headroomlabs-ai#1563))
([95abca3](headroomlabs-ai@95abca3))
* Vertex AI support for Claude Code with ANTHROPIC_VERTEX_BASE_URL
([headroomlabs-ai#1393](headroomlabs-ai#1393))
([cff7247](headroomlabs-ai@cff7247))
* **wrap:** detach the shared proxy on Windows so it survives an
ungraceful agent close
([headroomlabs-ai#1464](headroomlabs-ai#1464))
([6cba441](headroomlabs-ai@6cba441))
* **wrap:** preserve custom Vertex base URL
([headroomlabs-ai#1477](headroomlabs-ai#1477))
([75427bb](headroomlabs-ai@75427bb))
* **wrap:** remove rtk instructions from Codex AGENTS.md on unwrap
([headroomlabs-ai#1604](headroomlabs-ai#1604))
([c9d717c](headroomlabs-ai@c9d717c))
</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>