15 Commits

  • feat(network-proxy): experimental local credential broker (#28034)
    ## Why
    
    Codex child processes can inherit injectable local credentials directly,
    which lets commands read and exfiltrate the real values. This
    experimental slice keeps supported workflows working while moving those
    credentials behind the managed network proxy.
    
    This PR contains only the proxy-owned broker implementation. The Codex
    config and runtime integration is stacked separately in #29752.
    
    ## What changed
    
    - discover supported credentials during child setup, retain real values
    only in the in-memory proxy broker, and replace them with shaped dummy
    values
    - require a presented dummy to select a stored credential and preserve
    unrelated explicit authorization headers
    - bind GitHub cloud, GitHub Enterprise, and OpenAI credentials to their
    intended hosts
    - inject credentials only into TLS traffic by default; plaintext
    injection requires the explicit dangerous opt-in
    - use TLS ClientHello routing for CONNECT so non-TLS protocols remain
    opaque tunnels
    - expose a pure API that identifies environment keys still holding
    broker-generated dummies without mutating the caller's environment
    
    ## Scope
    
    - supported credentials: `GH_TOKEN`, `GITHUB_TOKEN`,
    `GH_ENTERPRISE_TOKEN`, `GITHUB_ENTERPRISE_TOKEN`, and `OPENAI_API_KEY`
    - GitHub cloud credentials match `github.com`, `api.github.com`, and
    `*.ghe.com`
    - GitHub Enterprise credentials match only the normalized non-cloud
    `GH_HOST`
    - OpenAI API keys match only `api.openai.com`
    - this does not cover SSH agents, kube client certificates, filesystem
    secret discovery, or context-injected secret scrubbing
    
    ## Validation
    
    - `just test -p codex-network-proxy` (191 passed)
    - focused opaque CONNECT, plaintext opt-in, dummy-selection, and
    child-isolation regressions passed
    - scoped Clippy check for `codex-network-proxy` passed
    
    ---------
    
    Co-authored-by: viyatb-oai <viyatb@openai.com>
    Co-authored-by: Codex <noreply@openai.com>
  • Honor startup custom CA bundles with managed MITM (#29014)
    ## Why
    
    When Codex starts with a custom CA override such as
    `SSL_CERT_FILE=/path/to/corp-ca.pem codex`, `rustls-native-certs` treats
    that override as a replacement for the platform trust store. The managed
    proxy then rewrites child CA variables to its generated bundle, so the
    custom root or the ordinary platform roots can be lost. The proxy's
    upstream TLS connector must trust the same roots or private and
    corporate upstream certificates still fail after interception.
    
    ## What
    
    - load platform-native roots without consulting inherited CA override
    variables
    - append certificates from the existing curated startup CA file
    variables and `SSL_CERT_DIR`
    - share those platform and startup roots with the MITM upstream rustls
    connector
    - exclude the Codex managed MITM CA from upstream trust
    - normalize OpenSSL `TRUSTED CERTIFICATE` blocks while dropping trailing
    trust metadata
    - skip an inherited current Codex-managed bundle so nested launches do
    not duplicate it
    - append the Codex managed MITM CA to the child-facing bundle
    - copy certificate material only, so a private key or unrelated text
    colocated in a startup file is never exposed through the public bundle
    
    This is intentionally limited to CA paths present when Codex starts. It
    does not parse inline shell assignments or add per-command bundle
    materialization.
    
    This changes only `codex-network-proxy` and dependency metadata; it does
    not touch `codex-core` or sandbox orchestration.
    
    ## Validation
    
    - `just test -p codex-network-proxy`
    - includes an end-to-end upstream TLS test using a server trusted only
    by the startup custom CA
    - `just fix -p codex-network-proxy`
    - `just bazel-lock-check`
  • [codex] Remove async_trait from first-party code (#27475)
    ## Why
    
    First-party async traits should expose their `Send` contracts explicitly
    without requiring `async_trait`. This completes the migration pattern
    established in #27303 and #27304.
    
    ## What changed
    
    - Replaced the remaining first-party `async_trait` traits with native
    return-position `impl Future + Send` where statically dispatched and
    explicit boxed `Send` futures where object safety is required.
    - Kept implementations behavior-preserving, outlining existing async
    bodies into inherent methods where that keeps the diff reviewable.
    - Removed all direct first-party `async-trait` dependencies and the
    workspace dependency declaration.
    - Added a cargo-deny policy that permits `async-trait` only through the
    remaining transitive wrapper crates.
    - Updated `rand` from 0.8.5 to 0.8.6 to resolve RUSTSEC-2026-0097 and
    keep the full cargo-deny check passing.
    
    ## Validation
    
    - `just test -p codex-exec-server`: 216 passed, 2 skipped.
    - `just test -p codex-model-provider`: 39 passed.
    - `just test -p codex-core` and `just test`: changed tests passed;
    remaining failures are environment-sensitive suites unrelated to this
    migration.
    - `cargo deny check`
    - `just fix`
    - `just fmt`
    - `cargo shear`
    - `just bazel-lock-check`
  • Wire managed MITM CA trust into child env (#22668)
    ## Stack
    1. Parent PR: #18240 uses named MITM permissions config.
    2. This PR wires managed MITM CA trust into spawned child processes.
    
    ## Why
    When Codex terminates HTTPS for limited mode or MITM hooks, child HTTPS
    clients need to trust Codex's managed MITM CA. Exporting proxy URLs
    alone is not enough, but blindly replacing user CA settings would be
    wrong: it can break custom enterprise/test roots, leak unreadable CA
    files into generated bundles, or make the child env disagree with its
    sandbox policy.
    
    ## Summary
    1. Build immutable managed CA bundles under `$CODEX_HOME/proxy` that
    include native roots, the managed MITM CA, and only inherited or
    command-scoped CA bundles the child is allowed to read.
    2. Export curated CA env vars alongside managed proxy env vars while
    preserving user CA override semantics, including nested Codex
    `SSL_CERT_FILE` precedence.
    3. Thread generated CA bundle paths into child sandbox readable roots,
    including debug sandbox execution, so the exported env vars work inside
    sandboxed commands.
    4. Remove only Codex-generated MITM CA bundle env when a child
    intentionally drops managed proxying for escalation or no-proxy retry.
    5. Document the managed CA bundle behavior and cover env injection,
    per-child bundle generation, sandbox readable roots, and no-proxy
    cleanup in tests.
    
    ## Validation
    1. Ran `just test -p codex-network-proxy`.
    2. Ran `just test -p codex-protocol`.
    3. Ran `just fix -p codex-network-proxy -p codex-protocol`.
    4. Tried focused `codex-core` validation, but the crate currently fails
    to compile in `core/tests/suite/guardian_review.rs` because an existing
    `Op::UserInput` initializer is missing `additional_context`.
    
    ---------
    
    Co-authored-by: Eva Wong <evawong@openai.com>
  • Disable empty Cargo test targets (#21584)
    ## Summary
    
    `cargo test` has entails both running standard Rust tests and doctests.
    It turns out that the doctest discovery is fairly slow, and it's a cost
    you pay even for crates that don't include any doctests.
    
    This PR disables doctests with `doctest = false` for crates that lack
    any doctests.
    
    For the collection of crates below, this speeds up test execution by
    >4x.
    
    E.g., before this PR:
    
    ```
    Benchmark 1: cargo test     -p codex-utils-absolute-path     -p codex-utils-cache     -p codex-utils-cli     -p codex-utils-home-dir     -p codex-utils-output-truncation     -p codex-utils-path     -p codex-utils-string     -p codex-utils-template     -p codex-utils-elapsed     -p codex-utils-json-to-toml
      Time (mean ± σ):      1.849 s ±  4.455 s    [User: 0.752 s, System: 1.367 s]
      Range (min … max):    0.418 s … 14.529 s    10 runs
    ```
    
    And after:
    
    ```
    Benchmark 1: cargo test     -p codex-utils-absolute-path     -p codex-utils-cache     -p codex-utils-cli     -p codex-utils-home-dir     -p codex-utils-output-truncation     -p codex-utils-path     -p codex-utils-string     -p codex-utils-template     -p codex-utils-elapsed     -p codex-utils-json-to-toml
      Time (mean ± σ):     428.6 ms ±   6.9 ms    [User: 187.7 ms, System: 219.7 ms]
      Range (min … max):   418.0 ms … 436.8 ms    10 runs
    ```
    
    For a single crate, with >2x speedup, before:
    
    ```
    Benchmark 1: cargo test -p codex-utils-string
      Time (mean ± σ):     491.1 ms ±   9.0 ms    [User: 229.8 ms, System: 234.9 ms]
      Range (min … max):   480.9 ms … 512.0 ms    10 runs
    ```
    
    And after:
    
    ```
    Benchmark 1: cargo test -p codex-utils-string
      Time (mean ± σ):     213.9 ms ±   4.3 ms    [User: 112.8 ms, System: 84.0 ms]
      Range (min … max):   206.8 ms … 221.0 ms    13 runs
    ```
    
    Co-authored-by: Codex <noreply@openai.com>
  • ci: verify codex-rs Cargo manifests inherit workspace settings (#16353)
    ## Why
    
    Bazel clippy now catches lints that `cargo clippy` can still miss when a
    crate under `codex-rs` forgets to opt into workspace lints. The concrete
    example here was `codex-rs/app-server/tests/common/Cargo.toml`: Bazel
    flagged a clippy violation in `models_cache.rs`, but Cargo did not
    because that crate inherited workspace package metadata without
    declaring `[lints] workspace = true`.
    
    We already mirror the workspace clippy deny list into Bazel after
    [#15955](https://github.com/openai/codex/pull/15955), so we also need a
    repo-side check that keeps every `codex-rs` manifest opted into the same
    workspace settings.
    
    ## What changed
    
    - add `.github/scripts/verify_cargo_workspace_manifests.py`, which
    parses every `codex-rs/**/Cargo.toml` with `tomllib` and verifies:
      - `version.workspace = true`
      - `edition.workspace = true`
      - `license.workspace = true`
      - `[lints] workspace = true`
    - top-level crate names follow the `codex-*` / `codex-utils-*`
    conventions, with explicit exceptions for `windows-sandbox-rs` and
    `utils/path-utils`
    - run that script in `.github/workflows/ci.yml`
    - update the current outlier manifests so the check is enforceable
    immediately
    - fix the newly exposed clippy violations in the affected crates
    (`app-server/tests/common`, `file-search`, `feedback`,
    `shell-escalation`, and `debug-client`)
    
    
    
    
    
    
    ---
    [//]: # (BEGIN SAPLING FOOTER)
    Stack created with [Sapling](https://sapling-scm.com). Best reviewed
    with [ReviewStack](https://reviewstack.dev/openai/codex/pull/16353).
    * #16351
    * __->__ #16353
  • feat(network-proxy): add embedded OTEL policy audit logging (#12046)
    **PR Summary**
    
    This PR adds embedded-only OTEL policy audit logging for
    `codex-network-proxy` and threads audit metadata from `codex-core` into
    managed proxy startup.
    
    ### What changed
    - Added structured audit event emission in `network_policy.rs` with
    target `codex_otel.network_proxy`.
    - Emitted:
    - `codex.network_proxy.domain_policy_decision` once per domain-policy
    evaluation.
      - `codex.network_proxy.block_decision` for non-domain denies.
    - Added required policy/network fields, RFC3339 UTC millisecond
    `event.timestamp`, and fallback defaults (`http.request.method="none"`,
    `client.address="unknown"`).
    - Added non-domain deny audit emission in HTTP/SOCKS handlers for
    mode-guard and proxy-state denies, including unix-socket deny paths.
    - Added `REASON_UNIX_SOCKET_UNSUPPORTED` and used it for unsupported
    unix-socket auditing.
    - Added `NetworkProxyAuditMetadata` to runtime/state, re-exported from
    `lib.rs` and `state.rs`.
    - Added `start_proxy_with_audit_metadata(...)` in core config, with
    `start_proxy()` delegating to default metadata.
    - Wired metadata construction in `codex.rs` from session/auth context,
    including originator sanitization for OTEL-safe tagging.
    - Updated `network-proxy/README.md` with embedded-mode audit schema and
    behavior notes.
    - Refactored HTTP block-audit emission to a small local helper to reduce
    duplication.
    - Preserved existing unix-socket proxy-disabled host/path behavior for
    responses and blocked history while using an audit-only endpoint
    override (`server.address="unix-socket"`, `server.port=0`).
    
    ### Explicit exclusions
    - No standalone proxy OTEL startup work.
    - No `main.rs` binary wiring.
    - No `standalone_otel.rs`.
    - No standalone docs/tests.
    
    ### Tests
    - Extended `network_policy.rs` tests for event mapping, metadata
    propagation, fallbacks, timestamp format, and target prefix.
    - Extended HTTP tests to assert unix-socket deny block audit events.
    - Extended SOCKS tests to cover deny emission from handler deny
    branches.
    - Added/updated core tests to verify audit metadata threading into
    managed proxy state.
    
    ### Validation run
    - `just fmt`
    - `cargo test -p codex-network-proxy` 
    - `cargo test -p codex-core` ran with one unrelated flaky timeout
    (`shell_snapshot::tests::snapshot_shell_does_not_inherit_stdin`), and
    the test passed when rerun directly 
    
    ---------
    
    Co-authored-by: viyatb-oai <viyatb@openai.com>
  • feat(network-proxy): add MITM support and gate limited-mode CONNECT (#9859)
    ## Description
    - Adds MITM support (CA load/issue, TLS termination, optional body
    inspection).
    - Adds `codex-network-proxy init` to create
    `CODEX_HOME/network_proxy/mitm`.
    - Enforces limited-mode HTTPS correctly: `CONNECT` requires MITM,
    otherwise blocked with `mitm_required`.
    - Keeps `origin/main` layering/reload semantics (managed layers included
    in reload checks).
    - Centralizes block reasons (`REASON_MITM_REQUIRED`) and removes
    `println!`.
    - Scope is MITM-only (no SOCKS changes).
    
    gated by `mitm=false` (default)
  • Refactor network approvals to host/protocol/port scope (#12140)
    ## Summary
    Simplify network approvals by removing per-attempt proxy correlation and
    moving to session-level approval dedupe keyed by (host, protocol, port).
    Instead of encoding attempt IDs into proxy credentials/URLs, we now
    treat approvals as a destination policy decision.
    
    - Concurrent calls to the same destination share one approval prompt.
    - Different destinations (or same host on different ports) get separate
    prompts.
    - Allow once approves the current queued request group only.
    - Allow for session caches that (host, protocol, port) and auto-allows
    future matching requests.
    - Never policy continues to deny without prompting.
    
    Example:
    - 3 calls: 
      - a.com (line 443)
      - b.com (line 443)
      - a.com (line 443)
    => 2 prompts total (a, b), second a waits on the first decision.
    - a.com:80 is treated separately from a.com line 443
    
    ## Testing
    - `just fmt` (in `codex-rs`)
    - `cargo test -p codex-core tools::network_approval::tests`
    - `cargo test -p codex-core` (unit tests pass; existing
    integration-suite failures remain in this environment)
  • feat(network-proxy): structured policy signaling and attempt correlation to core (#11662)
    ## Summary
    When network requests were blocked, downstream code often had to infer
    ask vs deny from free-form response text. That was brittle and led to
    incorrect approval behavior.
    This PR fixes the proxy side so blocked decisions are structured and
    request metadata survives reliably.
    
    ## Description
    - Blocked proxy responses now carry consistent structured policy
    decision data.
    - Request attempt metadata is preserved across proxy env paths
    (including ALL_PROXY flows).
    - Header stripping was tightened so we still remove unsafe forwarding
    headers, but keep metadata needed for policy handling.
    - Block messages were clarified (for example, allowlist miss vs explicit
    deny).
    - Added unified violation log entries so policy failures can be
    inspected in one place.
    - Added/updated tests for these behaviors.
    
    ---------
    
    Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
  • chore: put crypto provider logic in a shared crate (#11294)
    Ensures a process-wide rustls crypto provider is installed.
    
    Both the `codex-network-proxy` and `codex-api` crates need this.
  • feat: enable premessage-deflate for websockets (#10966)
    note:
    unfortunately, tokio-tungstenite / tungstenite upgrade triggers some
    problems with linker of rama-tls-boring with openssl:
    ```
    error: linking with `/Users/apanasenko/Library/Caches/cargo-zigbuild/0.20.1/zigcc-x86_64-unknown-linux-musl-ff6a.sh` failed: exit status: 1
      |
      = note:  "/Users/apanasenko/Library/Caches/cargo-zigbuild/0.20.1/zigcc-x86_64-unknown-linux-musl-ff6a.sh" "-m64" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/rcrt1.o" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crti.o" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtbeginS.o" "<1 object files omitted>" "-Wl,--as-needed" "-Wl,-Bstatic" "/var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/{liblzma_sys-662a82316f96ec30,libbzip2_sys-bf78a2d58d5cbce6,liblibsqlite3_sys-6c004987fd67a36a,libtree_sitter_bash-220b99a97d331ab7,libtree_sitter-858f0a1dbfea58bd,libzstd_sys-6eb237deec748c5b,libring-2a87376483bf916f,libopenssl_sys-7c189e68b37fe2bb,liblibz_sys-4344eef4345520b1,librama_boring_sys-0414e98115015ee0}.rlib" "-lc++" "-lc++abi" "-lunwind" "-lc" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/libcompiler_builtins-*.rlib" "-L" "/var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/raw-dylibs" "-Wl,-Bdynamic" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-nostartfiles" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/libz-sys-ff5ea50d88c28ffb/out/lib" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/ring-bdec3dddc19f5a5e/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/openssl-sys-96e0870de3ca22bc/out/openssl-build/install/lib" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/zstd-sys-0cc37a5da1481740/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/tree-sitter-72d2418073317c0f/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/tree-sitter-bash-bfd293a9f333ce6a/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/libsqlite3-sys-b78b2cfb81a330fc/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/bzip2-sys-69a145cc859ef275/out/lib" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/lzma-sys-07e92d0b6baa6fd4/out" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/build/crypto/" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/build/ssl/" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/build/" "-L" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/build" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib" "-o" "/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/deps/codex_network_proxy-d08268b863517761" "-Wl,--gc-sections" "-static-pie" "-Wl,-z,relro,-z,now" "-Wl,-O1" "-Wl,--strip-all" "-nodefaultlibs" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtendS.o" "<sysroot>/lib/rustlib/x86_64-unknown-linux-musl/lib/self-contained/crtn.o"
      = note: some arguments are omitted. use `--verbose` to show all linker arguments
      = note: warning: ignoring deprecated linker optimization setting '1'
              warning: unable to open library directory '/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/build/crypto/': FileNotFound
              ld.lld: error: duplicate symbol: SSL_export_keying_material
              >>> defined at ssl_lib.c:3816 (ssl/ssl_lib.c:3816)
              >>>            libssl-lib-ssl_lib.o:(SSL_export_keying_material) in archive /var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/libopenssl_sys-7c189e68b37fe2bb.rlib
              >>> defined at t1_enc.cc:205 (/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/boringssl/ssl/t1_enc.cc:205)
              >>>            t1_enc.cc.o:(.text.SSL_export_keying_material+0x0) in archive /var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/librama_boring_sys-0414e98115015ee0.rlib
    
              ld.lld: error: duplicate symbol: d2i_ASN1_TIME
              >>> defined at a_time.c:27 (crypto/asn1/a_time.c:27)
              >>>            libcrypto-lib-a_time.o:(d2i_ASN1_TIME) in archive /var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/libopenssl_sys-7c189e68b37fe2bb.rlib
              >>> defined at a_time.cc:34 (/Users/apanasenko/code/codex/codex-rs/target/x86_64-unknown-linux-musl/release/build/rama-boring-sys-0bc2dfbf669addc4/out/boringssl/crypto/asn1/a_time.cc:34)
              >>>            a_time.cc.o:(.text.d2i_ASN1_TIME+0x0) in archive /var/folders/kt/52y_g75x3ng8ktvk3rfwm6400000gp/T/rustcyGQdYm/librama_boring_sys-0414e98115015ee0.rlib
    ``` 
    
    that force me to migrate away from rama-tls-boring to rama-tls-rustls
    and pin `ring` for rustls.
  • feat(network-proxy): add a SOCKS5 proxy with policy enforcement (#9803)
    ### Summary
    - Adds an optional SOCKS5 listener via `rama-socks5`
    - SOCKS5 is disabled by default and gated by config
    - Reuses existing policy enforcement and blocked-request recording
    - Blocks SOCKS5 in limited mode to prevent method-policy bypass
    - Applies bind clamping to the SOCKS5 listener
    
    ### Config
    New/used fields under `network_proxy`:
    - `enable_socks5`
    - `socks_url`
    - `enable_socks5_udp`
    
    ### Scope
    - Changes limited to `codex-rs/network-proxy` (+ `codex-rs/Cargo.lock`)
    
    ### Testing
    ```bash
    cd codex-rs
    just fmt
    cargo test -p codex-network-proxy --offline
  • feat: introducing a network sandbox proxy (#8442)
    This add a new crate, `codex-network-proxy`, a local network proxy
    service used by Codex to enforce fine-grained network policy (domain
    allow/deny) and to surface blocked network events for interactive
    approvals.
    
    - New crate: `codex-rs/network-proxy/` (`codex-network-proxy` binary +
    library)
    - Core capabilities:
      - HTTP proxy support (including CONNECT tunneling)
      - SOCKS5 proxy support (in the later PR)
    - policy evaluation (allowed/denied domain lists; denylist wins;
    wildcard support)
      - small admin API for polling/reload/mode changes
    - optional MITM support for HTTPS CONNECT to enforce “limited mode”
    method restrictions (later PR)
    
    Will follow up integration with codex in subsequent PRs.
    
    ## Testing
    
    - `cd codex-rs && cargo build -p codex-network-proxy`
    - `cd codex-rs && cargo run -p codex-network-proxy -- proxy`