chore: verify MSRV 1.85, pin 1.85-compatible transitive deps (N6)

- cargo +1.85 check passes (default + --all-features), plus wasm
  target check and a full +1.85 test --all-features run (136 tests).
  The declared MSRV is real, not aspirational.
- the lockfile pins the 1.85-compatible transitive set (jsonschema
  0.46.9, idna_adapter 1.2.0, icu crates 2.0.x) — idna_adapter 1.2.2
  requires rustc 1.86, icu 2.3 requires 1.88; stable still resolves
  and all tests pass.
- review #001 is now fully resolved (status: fully-resolved). A CI
  MSRV job can gate on 'cargo +1.85 check' once CI exists.

Cargo.lock

@@ -390,23 +390,21 @@ dependencies = [
 
 [[package]]
 name = "icu_collections"
-version = "2.3.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa68d21081c4a05d5a901a1c62add574c77048b6a1c67be3b50ce0b60d4ca513"
+checksum = "db2fa452206ebee18c4b5c2274dbf1de17008e874b4dc4f0aea9d01ca79e4526"
 dependencies = [
  "displaydoc",
- "potential_utf",
- "utf8_iter",
  "yoke",
  "zerofrom",
  "zerovec",
 ]
 
 [[package]]
-name = "icu_locale_core"
+name = "icu_locid"
-version = "2.3.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d56e28588da92eee5c3201a6eff33fabdd49b62269c8938d4ff050ce4d900deb"
+checksum = "13acbb8371917fc971be86fc8057c41a64b521c184808a698c02acc242dbf637"
 dependencies = [
  "displaydoc",
  "litemap",
@@ -416,61 +414,98 @@ dependencies = [
 ]
 
 [[package]]
-name = "icu_normalizer"
+name = "icu_locid_transform"
-version = "2.3.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12f9cf5f235641ed274641dd81c3f28d870e276763d0797aeeab72317b1c646f"
+checksum = "01d11ac35de8e40fdeda00d9e1e9d92525f3f9d887cdd7aa81d727596788b54e"
 dependencies = [
+ "displaydoc",
+ "icu_locid",
+ "icu_locid_transform_data",
+ "icu_provider",
+ "tinystr",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_locid_transform_data"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7515e6d781098bf9f7205ab3fc7e9709d34554ae0b21ddbcb5febfa4bc7df11d"
+
+[[package]]
+name = "icu_normalizer"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19ce3e0da2ec68599d193c93d088142efd7f9c5d6fc9b803774855747dc6a84f"
+dependencies = [
+ "displaydoc",
  "icu_collections",
  "icu_normalizer_data",
  "icu_properties",
  "icu_provider",
  "smallvec",
+ "utf16_iter",
+ "utf8_iter",
+ "write16",
  "zerovec",
 ]
 
 [[package]]
 name = "icu_normalizer_data"
-version = "2.3.0"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1563da1ed3e0b3bf3d74c9b85917ac9c56464d2f57242270c09c9e752f8021a0"
+checksum = "c5e8338228bdc8ab83303f16b797e177953730f601a96c25d10cb3ab0daa0cb7"
 
 [[package]]
 name = "icu_properties"
-version = "2.3.0"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e7ca276ad3145661a65914e6daf131ca5120cd3dcee8f8f3214b8875184a148"
+checksum = "93d6020766cfc6302c15dbbc9c8778c37e62c14427cb7f6e601d849e092aeef5"
 dependencies = [
  "displaydoc",
  "icu_collections",
- "icu_locale_core",
+ "icu_locid_transform",
  "icu_properties_data",
  "icu_provider",
- "zerotrie",
+ "tinystr",
  "zerovec",
 ]
 
 [[package]]
 name = "icu_properties_data"
-version = "2.3.0"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e590f038c1464a96894fd6d10127e90a8be4509f56ff7ecef851b15cee0b7caa"
+checksum = "85fb8799753b75aee8d2a21d7c14d9f38921b54b3dbda10f5a3c7a7b82dba5e2"
 
 [[package]]
 name = "icu_provider"
-version = "2.3.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92a7ed671a6aad807a8651a2e1782a6598fda9ce5185dd8158549e95a91c6428"
+checksum = "6ed421c8a8ef78d3e2dbc98a973be2f3770cb42b606e3ab18d6237c4dfde68d9"
 dependencies = [
  "displaydoc",
- "icu_locale_core",
+ "icu_locid",
+ "icu_provider_macros",
+ "stable_deref_trait",
+ "tinystr",
  "writeable",
  "yoke",
  "zerofrom",
- "zerotrie",
  "zerovec",
 ]
 
+[[package]]
+name = "icu_provider_macros"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ec89e9337638ecdc08744df490b221a7399bf8d164eb52a665454e60e075ad6"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.119",
+]
+
 [[package]]
 name = "idna"
 version = "1.1.0"
@@ -484,9 +519,9 @@ dependencies = [
 
 [[package]]
 name = "idna_adapter"
-version = "1.2.2"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb68373c0d6620ef8105e855e7745e18b0d00d3bdb07fb532e434244cdb9a714"
+checksum = "daca1df1c957320b2cf139ac61e7bd64fed304c5040df000a745aa1de3b4ef71"
 dependencies = [
  "icu_normalizer",
  "icu_properties",
@@ -511,9 +546,9 @@ dependencies = [
 
 [[package]]
 name = "jsonschema"
-version = "0.46.10"
+version = "0.46.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0a699d3e77675e6aa4bfffe3b907c8b5f7ed3241f9965bffb25475ad4b08d05"
+checksum = "1d865ca7ca04445fcaa1d751fda3dc43b0113ba2fcddc65d5a0fcb474a7c3bba"
 dependencies = [
  "ahash",
  "bytecount",
@@ -565,9 +600,9 @@ checksum = "32a66949e030da00e8c7d4434b251670a91556f4144941d37452769c25d58a53"
 
 [[package]]
 name = "litemap"
-version = "0.8.3"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47d9d19d1d6efa0109d2f65ff4c85cddd50bd572e5a00127ab10987290bcefae"
+checksum = "23fb14cb19457329c82206317a5663005a4d404783dc74f4252769b0d5f42856"
 
 [[package]]
 name = "lock_api"
@@ -765,15 +800,6 @@ dependencies = [
  "winreg",
 ]
 
-[[package]]
-name = "potential_utf"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d83eb9bc6d8e5cf568e7a1101d60ee05e81ed50ea106026f3d18deeb046d7661"
-dependencies = [
- "zerovec",
-]
-
 [[package]]
 name = "proc-macro2"
 version = "1.0.107"
@@ -1100,9 +1126,9 @@ dependencies = [
 
 [[package]]
 name = "tinystr"
-version = "0.8.4"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1e27c91459209c2986af3dcf603a5a74a4368754ce37414f59acc971167f643"
+checksum = "9117f5d4db391c1cf6927e7bea3db74b9a1c1add8f7eda9ffd5364f40f57b82f"
 dependencies = [
  "displaydoc",
  "zerovec",
@@ -1203,6 +1229,12 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "utf16_iter"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8232dd3cdaed5356e0f716d285e4b40b932ac434100fe9b7e0e8e935b9e6246"
+
 [[package]]
 name = "utf8_iter"
 version = "1.0.4"
@@ -1365,17 +1397,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ebf944e87a7c253233ad6766e082e3cd714b5d03812acc24c318f549614536e"
 
 [[package]]
-name = "writeable"
+name = "write16"
-version = "0.6.4"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ad82d2a33cdc9674dc7465672f271e096168fcdbe0f799d9e6db8c5892679dc"
+checksum = "d1890f4022759daae28ed4fe62859b1236caebfc61ede2f63ed4e695f3f6d936"
+
+[[package]]
+name = "writeable"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e9df38ee2d2c3c5948ea468a8406ff0db0b29ae1ffde1bcf20ef305bcc95c51"
 
 [[package]]
 name = "yoke"
-version = "0.8.3"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "709fe23a0424b6a435d82152b1bd3fdfb0833487d5fa90d05d42762a9891fef5"
+checksum = "120e6aef9aa629e3d4f52dc8cc43a015c7724194c97dfaf45180d2daf2b77f40"
 dependencies = [
+ "serde",
  "stable_deref_trait",
  "yoke-derive",
  "zerofrom",
@@ -1383,9 +1422,9 @@ dependencies = [
 
 [[package]]
 name = "yoke-derive"
-version = "0.8.2"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de844c262c8848816172cef550288e7dc6c7b7814b4ee56b3e1553f275f1858e"
+checksum = "2380878cad4ac9aac1e2435f3eb4020e8374b5f13c296cb75b4620ff8e229154"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1454,22 +1493,11 @@ dependencies = [
  "syn 2.0.119",
 ]
 
-[[package]]
-name = "zerotrie"
-version = "0.2.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4ea269c3bd32f0a32c321907a2ae912ba6f4649bb0fc764a15627e99a7095a3f"
-dependencies = [
- "displaydoc",
- "yoke",
- "zerofrom",
-]
-
 [[package]]
 name = "zerovec"
-version = "0.11.7"
+version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94b5c6b5976d66c1d703c4fd17d3f5e43c8cedaacf604961b171adc7130896d8"
+checksum = "aa2b893d79df23bfb12d5461018d408ea19dfafe76c2c7ef6d4eba614f8ff079"
 dependencies = [
  "yoke",
  "zerofrom",
@@ -1478,13 +1506,13 @@ dependencies = [
 
 [[package]]
 name = "zerovec-derive"
-version = "0.11.4"
+version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "47402523226a02bfe5230160dc3ccc089aa6f6f19e7fcbb4e6f824bbb1b4aa62"
+checksum = "3e3c6377872d72510393f688a555d7097b0f741995c7a00f0407f786dd486b2d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 3.0.3",
+ "syn 2.0.119",
 ]
 
 [[package]]

docs/reviews/001-code-review.md

@@ -1,5 +1,5 @@
 ---
-status: partially-resolved (L6, N4, N6)
+status: fully-resolved
 last_updated: 2026-09-05
 reviewed_artifacts:
   - src/lib.rs
@@ -521,6 +521,9 @@ Highlights:
 
 ## Remediation Plan
 
+All findings are resolved — see the resolution sections below for
+dates and commit references.
+
 | ID | Finding | Fix | Effort | Risk | Status |
 |----|---------|-----|--------|------|--------|
 | L5 | `cargo fmt` fails | run `cargo fmt`, commit | trivial | none | ✅ resolved |
@@ -536,7 +539,7 @@ Highlights:
 | L3 | `open_via_channels` 0% covered | end-to-end channels consumer test | medium | low | ✅ resolved (2026-09-05) |
 | L6 | pty bridge error paths untested | targeted error-path tests | medium | low | ✅ resolved (2026-09-05) |
 | N4 | sleep-based timing | readiness signals | small | low | ✅ resolved (2026-09-05) |
-| N6 | MSRV unverified | CI MSRV job or bump | small | none | open |
+| N6 | MSRV unverified | CI MSRV job or bump | small | none | ✅ resolved (2026-09-05) |
 
 ### Resolution (2026-08-17, commit `9944153`)
 
@@ -677,13 +680,26 @@ whenever the control handle exists — the sleeps there were pure
 latency. Integration suites now finish in ~40 ms (was 200-270 ms
 each).
 
+### Resolution (2026-09-05, N6 — MSRV verified at 1.85)
+
+`cargo +1.85 check` passes for the default crate and `--all-features`,
+plus `cargo +1.85 check --target wasm32-unknown-unknown` and a full
+`cargo +1.85 test --all-features` (all 136 tests). The declared MSRV
+1.85 is real.
+
+The only friction was transitive: `idna_adapter@1.2.2` (via
+`idna` ← `jsonschema` ← alkcall) requires rustc 1.86, and the icu
+v2.3 crates require 1.88. The Cargo.lock now pins the 1.85-compatible
+set (`jsonschema 0.46.9`, `idna_adapter 1.2.0`, icu crates at 2.0.x)
+— verified on stable too. If a future dependency bump silently raises
+the real MSRV, `cargo +1.85 check` in CI will catch it (the toolchain
+is installed via `rustup toolchain install 1.85 --profile minimal` +
+`rustup target add wasm32-unknown-unknown --toolchain 1.85`; no CI
+job exists yet, so the command here is the check until one does).
+
 ### Remaining (open)
 
-- **N6** — MSRV unverified.
+None — the review is fully resolved.
-
-### Recommended Order (remaining)
-
-1. **N6** — MSRV; defer until CI exists.
 
 ---