fix(anthropic): strip styled Claude model ids

[Kumario1]

Description

Fixes #626 by normalizing Anthropic/Claude model ids that contain ANSI escape sequences or dangling style suffixes before provider lookups and upstream forwarding. The branch has been updated onto current main and the proxy handler conflicts have been resolved.

Type of Change

• Bug fix
• New feature
• Documentation
• Refactor
• Tests only

Changes Made

• Normalize Anthropic model ids before context/pricing lookup.
• Sanitize Anthropic /v1/models metadata and styled /v1/models/{id} passthrough paths.
• Sanitize /v1/messages request body model ids before upstream forwarding.
• Resolved current-main conflicts while preserving newer model_override and streaming passthrough behavior.

Testing

• Unit tests
• Route/proxy tests
• Lint/static checks
• Manual testing

Test Output

UV_SKIP_WHEEL_FILENAME_CHECK=1 uv run --with pytest --with fastapi --with httpx --with uvicorn --with h2 python -m pytest tests/test_providers/test_anthropic.py tests/test_provider_proxy_routes.py::test_anthropic_model_metadata_strips_ansi_model_ids tests/test_provider_proxy_routes.py::test_anthropic_model_detail_path_strips_ansi_model_id tests/test_provider_proxy_routes.py::test_anthropic_messages_strips_ansi_model_id_before_upstream -q
17 passed, 2 warnings in 39.91s

UV_SKIP_WHEEL_FILENAME_CHECK=1 uv run --with ruff ruff check headroom/providers/anthropic.py headroom/proxy/handlers/openai.py headroom/proxy/handlers/anthropic.py tests/test_providers/test_anthropic.py tests/test_provider_proxy_routes.py
All checks passed!

Real Behavior Proof

• Environment: Windows 11, Python 3.13.3, focused local worktree for PR fix(anthropic): strip styled Claude model ids #651 after merging current upstream/main.
• Exact command / steps: Merged current main, resolved conflicts in Anthropic/OpenAI proxy handlers, ran the PR's targeted provider/proxy tests and ruff checks.
• Observed result: Styled Anthropic model metadata, model-detail path, and messages upstream sanitization tests pass; ruff reports no issues.
• Not tested: Full repository mypy/pre-commit; existing unrelated Windows fcntl typing errors block full hook execution locally.

Review Readiness

• I have performed a self-review
• This PR is ready for human review

Description

This PR prepares fix(anthropic): strip styled Claude model ids for review by documenting the intended change, validation evidence, and remaining merge-readiness context.

Linked issues: #626

Type of Change

• Bug fix
• New feature
• Documentation
• Refactor
• Tests only

Changes Made

• Commit: fix(anthropic): normalize styled model ids
• Commit: fix(proxy): strip styled Anthropic model ids
• Commit: fix: format anthropic model sanitization
• Commit: Merge remote-tracking branch 'upstream/main' into review/pr-651
• Touches headroom/cache/dynamic_detector.py
• Touches headroom/providers/anthropic.py
• Touches headroom/proxy/handlers/anthropic.py
• Touches headroom/proxy/handlers/openai.py
• Touches tests/test_provider_proxy_routes.py
• Touches tests/test_providers/test_anthropic.py

Testing

• GitHub checks reviewed
• Metadata/template validation
• Local functional testing

Test Output

gh pr view 651 --repo chopratejas/headroom --json statusCheckRollup
- PR Governance / template: FAILURE
- CI / changes: SUCCESS
- Init E2E / docker-init-e2e: SUCCESS
- Wrap E2E / docker-wrap-e2e: SUCCESS
- Wrap Native E2E / wrap-native (ubuntu-latest): SUCCESS
- Wrap Native E2E / wrap-native (macos-latest): SUCCESS
- CI / commitlint: SUCCESS
- PR Governance / label: SUCCESS
- CI / lint: SUCCESS
- CI / build-wheel: SUCCESS
- CI / prefetch-model: SUCCESS
- CI / build: SUCCESS

Real Behavior Proof

• Environment: GitHub PR metadata and checks for chopratejas/headroom PR fix(anthropic): strip styled Claude model ids #651.
• Exact command / steps: Reviewed PR title, commits, changed files, linked issues, labels, and check rollup; appended this maintainer template completion block without replacing the author's original description.
• Observed result: PR body now contains all required governance sections, checked readiness fields, and a non-placeholder validation evidence block.
• Not tested: This pass updated PR metadata only; code validation remains represented by the linked GitHub checks and any author-provided evidence above.

Review Readiness

• I have performed a self-review
• This PR is ready for human review

[DevanshiVyas]

Thank you for your contribution! Issue 626 has also been addressed in PR. Are your changes still needed? Also, please verify your changes on top of the latest changes in main and add a testing section as mentioned in CONTRIBUTING.md

[JerrettDavis]

Thanks, this is a useful fix and the tests cover the important paths: provider lookup, Anthropic metadata, model-detail passthrough, and /v1/messages sanitization.

The branch is currently conflicted. Please rebase/update against current main and rerun CI so we can review the resolved proxy handler changes before merge.

[codecov]

Codecov Report

❌ Patch coverage is 90.56604% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
headroom/proxy/handlers/openai.py	84.21%	2 Missing and 1 partial ⚠️
headroom/cache/dynamic_detector.py	33.33%	1 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

PR governance

This PR follows the template and is marked ready for human review.

[JerrettDavis]

Maintainer follow-up: added the minimal headroom/cache/dynamic_detector.py guard for the full-repo mypy CI failure seen on this PR (_exemplar_embeddings can be None). Focused validation: ests/test_cache/test_dynamic_detector.py passed (35 passed, 3 skipped),
uff check headroom/cache/dynamic_detector.py passed, and mypy headroom/cache/dynamic_detector.py --ignore-missing-imports passed.