chore(tooling): adopt stable TypeScript 7 and Biome 2.6

biome.json

@@ -1,9 +1,9 @@
 {
-	"$schema": "https://biomejs.dev/schemas/2.3.5/schema.json",
+	"$schema": "https://biomejs.dev/schemas/2.6.3/schema.json",
 	"linter": {
 		"enabled": true,
 		"rules": {
-			"recommended": true,
+			"preset": "recommended",
 			"style": {
 				"noNonNullAssertion": "off",
 				"useConst": "error",

docs/dependency-maintenance.md

@@ -15,7 +15,7 @@ Keep each dependency's pins synchronized across consuming workspaces and example
 
 - Vitest and `@vitest/coverage-v8` use **4.1.12**, the patched 4.x release. The latest `vitest-evals` (**0.17.0**) requires `vitest >=4 <5`, so Vitest 5 is not compatible with the evaluation workspace.
 - `hosted-git-info` remains **9.0.3**. Version 10.1.1 requires Node `^22.22.2 || ^24.15.0 || >=26.0.0`, above the project's Node 22.19.0 minimum.
-- `@typescript/native-preview` has no stable release under that package name; do not replace its existing pin with another prerelease as part of a stable-only update.
+- `@typescript/native-preview` has no stable release under that package name; do not replace its existing pin with another prerelease as part of a stable-only update. Its existing pin remains available to workspace build scripts, while the root check uses stable TypeScript 7's `tsc`.
 
 ## Install tooling
 
@@ -29,6 +29,12 @@ If changed dependencies remain duplicated under workspaces, run `npm dedupe --pa
 
 The repository normally enforces a two-day minimum release age. Do not disable it without explicit approval. This update batch received approval to use `npm_config_min_release_age=0` on install commands only; `.npmrc` remains unchanged.
 
+## Development tooling
+
+Development tooling uses Biome **2.6.3**, TypeScript **7.0.2**, esbuild **0.28.2**, and tsx **4.23.15**. Biome's schema and recommended preset configuration are migrated together with newly enforced diagnostics. The TypeScript target is **ES2024**, matching Unicode-set regular expressions already used on supported Node runtimes. The relative-import policy checker uses TypeScript 7's exported native AST API (`typescript/unstable/ast` and `typescript/unstable/sync`); these API paths are unstable, so the exact compiler pin and syntax/diagnostic regression tests must move together. Temporary parser projects and native clients are cleaned up after every check.
+
+`diff` supplies its own declarations, so the obsolete `@types/diff` stub is no longer needed. The rimraf override is synchronized at **6.1.3** in the root and published CLI manifests/locks. Nanoid and protobufjs overrides remain in their consumers' compatible major lines rather than forcing unsupported transitive majors.
+
 ## Runtime libraries
 
 Runtime pins use keyring **2.1.2**, Chalk **6.0.1**, diff **9.0.0**, highlight.js **11.12.0**, and HTTP/HTTPS proxy agents **9.1.0**. Terminal tests use xterm/headless **6.0.0**. Node declarations are synchronized at **26.6.5**; the supported runtime minimum remains Node **22.19.0**, and no new runtime APIs are required.