test(mcp): prove tracedecay_remote_status behavior

[ScriptedAlchemy]

Summary

• Prove tracedecay_remote_status through real MCP tools/call responses, not handler-internal serialization.
• A fresh daemon-mounted Remote Brain returns the literal unconfigured read in JSON and Markdown.
• A server that never installed the reader returns the literal unavailable read, not an empty object or a JSON-RPC error.

Motivation

The tool's client-visible contract is a typed operational read. Existing dispatch coverage compares a fixture to its own serde output, which does not lock the JSON-RPC text a host actually receives.

Changes

• crates/tracedecay/tests/mcp_suite/mcp_handler_test/remote_status_test.rs calls the production composition and an unmounted MCP server the way a host does, and asserts the full JSON-RPC result against literal payloads.

Test plan

• REQUIRE_EXACT_TEST_COUNT=2 scripts/require-exact-test.sh cargo test -p tracedecay --features test-transport --test mcp_suite remote_status_test
• cargo nextest run --workspace --no-fail-fast not run; this change is one MCP behavior test
• cargo clippy not run workspace-wide
• No production code change; manual proof is the test execution itself

Checklist

• No changelog entry: test-only, no user-facing product change
• No secrets, credentials, or .env files included
• No breaking changes

  

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[ScriptedAlchemy]

Closing as superseded. A sibling change proving the same tool landed first as #1816.

Evidence from the triage: git log origin/master --diff-filter=A -- mcp_handler_test/remote_status_test.rs => 391c6a4 via branch pr1645/remote-status-proof; gh pr list --state merged 'remote status in:title' => 1816 pr1645/remote-status-proof 'prove remote status across the tools/call boundary'; same path added in both, 4 conflict hunks

Reopen if the landed version misses an assertion this branch carries; name it and it can be ported as a small follow-up.