fix: install.sh doctor readiness parsing uses outdated JSON schema

[vi70x3]

Problem

The run_doctor() function in install.sh parses the computer-use-linux doctor JSON output using the old schema:

ready="$(printf '%s' "${out}" | jq -r '.readiness.ready // false')"

and

printf '%s' "${out}" | jq -r '.readiness.checks[]? | select(.status != "ok") | ...'

However, the doctor output's readiness object no longer contains .ready (boolean) or .checks (array) fields. The current schema uses:

• .readiness.blockers (array of strings) — empty array means ready
• .readiness.can_build_accessibility_tree, .readiness.can_query_windows, etc. (booleans)
• .readiness.recommended_next_step (string)

Because .readiness.ready is now null, the jq expression .readiness.ready // false evaluates to false, causing install.sh to always report "doctor reports NOT ready" even when the system is fully provisioned.

Steps to Reproduce

1. Run ./install.sh on any system where the doctor would otherwise report ready (all checks pass, no blockers).
2. Observe Step 8 outputs ready: null and FAIL doctor reports NOT ready.
3. Run computer-use-linux doctor | jq '.readiness' directly — note the absence of .ready and .checks fields.

Expected Behavior

When the doctor has zero blockers, install.sh should report OK doctor reports ready.

Proposed Fix

Update the jq queries in run_doctor() to use the current schema:

• Replace .readiness.ready check with .readiness.blockers | length == 0
• Replace .readiness.checks[] failure extraction with .readiness.blockers[]

A fix has been prepared locally and tested — install.sh now correctly reports ready on a fully provisioned CachyOS/Hyprland system.

[avifenesh]

Hi @vi70x3 thanks for the issue and driving a pr!