fix(cli): repair bundled resource monitor permissions - #5448

Problem

On Linux, the Resource monitor diagnostics do not load. The Settings page reports Native unavailable and shows zeroed CPU, memory, process, and throughput values.

The native monitor binary is present at dist/resource-monitor/linux-x64/t3-resource-monitor, but the npm package publishes it with mode 0644 instead of an executable mode. T3 detects the bundled binary, rejects it as non-executable, and therefore never starts the native telemetry process.

This is not a CPU architecture, shared-library, or noexec mount problem: the affected binary is a valid Linux x64 ELF and its required libraries are available.

Fix

• distinguish bundled monitor candidates from explicitly configured override paths
• when a bundled POSIX monitor lacks execute bits, add them before resolving it
• retain the existing error for a monitor that still cannot be made executable
• do not mutate explicit user-supplied monitor override paths

This lets the diagnostics sidecar start even when npm packaging removes executable permissions from native files.

Regression coverage

One focused test creates a bundled monitor fixture with mode 0644, verifies resolution repairs it, and verifies it becomes executable. Existing coverage continues to ensure a non-executable explicit override is rejected.

Verification

• vp test run apps/server/src/resourceTelemetry/ResourceMonitorBinary.test.ts — 6 passed

Reproduction

t3@0.0.31 and the current nightly package both publish the Linux monitor without execute bits. After this change, retrying the monitor or restarting the server should populate the Resource monitor instead of showing Native unavailable.