fix(discover): rewrite dotnet test/restore/format, not just build

[maxmilian]

Summary

• rtk dotnet test, rtk dotnet restore, and rtk dotnet format proxies already exist and route to dedicated handlers, but rtk rewrite only matched dotnet build — so the Claude Code hook silently passed the other three through unfiltered. Fixes [rewrite] dotnet test|restore|format should auto-rewrite to rtk dotnet #1830.

Root cause

The dotnet rewrite rule in src/discover/rules.rs used pattern: r"^dotnet\s+build\b", covering only build. DotnetCommands::Test/Restore/Format all dispatch to real handlers (src/main.rs:1709-1711), so the proxies work when invoked directly — only the rewrite registry was missing them.

Fix

Widen the rule's pattern to ^dotnet\s+(build|test|restore|format)\b. The output filters already handle all four; this is purely a routing fix (one regex).

Tests

• test_rewrite_dotnet_subcommands — all four rewrite to rtk dotnet <sub>; dotnet publish / dotnet run (no proxy) are left untouched.
• Full suite: 1947 passed, clippy clean, cargo fmt --check clean.

Manual verification

dotnet build    -> rtk dotnet build
dotnet test     -> rtk dotnet test
dotnet restore  -> rtk dotnet restore
dotnet format   -> rtk dotnet format
dotnet publish  -> (not rewritten)

Scope

Only the four subcommands with existing proxies. dotnet build and the three new subcommands now share one rule and behave identically (same permission verdict / exit code). The exit-code (ask vs auto-allow) is governed by a separate permission layer and is unchanged by this routing fix.

[maxmilian]

Ran a fresh-context independent review (skeptical, diff + issue only). Verdict: no blockers. Two points addressed / noted:

• Hardened the test (pushed): added a trailing-args case (dotnet test --filter Category=Unit → preserved) and a word-boundary negative (dotnet builder → not rewritten), confirming \b stops at the subcommand.
• Kept the capturing group (build|test|restore|format) to stay consistent with the other multi-subcommand rules in rules.rs (git/gh/cargo/ruff/go), which capture for subcmd_savings lookup — and it leaves room for the follow-up below.

Follow-up (intentionally out of scope here): the rule's flat savings_pct: 70.0 now applies to all four subcommands. dotnet test likely compresses closer to ~90% (cf. cargo test/go test), so rtk discover will slightly undercount its savings. I left this out of a pure routing fix because I don't have reliable compression figures for restore/format and didn't want to guess. Happy to file a separate PR adding subcmd_savings overrides if maintainers want the report accuracy.