fix(analyzer): bound file analysis workers

[omribz156]

Closes #8046

Reason for Proposed Changes

• The analyzer currently starts one goroutine per candidate file.
• On very large repositories, that can create tens of thousands of goroutines during "Preparing Scan Assets" and trigger the thread-exhaustion crash reported in the issue.

Proposed Changes

• Replace per-file goroutine spawning with a bounded worker pool.
• Size the pool from GOMAXPROCS, capped at 128 workers and never larger than the candidate file count.
• Add unit coverage for the worker-count helper.

Verification

• go test ./pkg/analyzer -count=1
• go test ./pkg/scan -run "Test.*Analyze|Test.*Init|Test.*Prepare" -count=1
• git diff --check

This was implemented with Codex assistance, with the final patch kept focused and manually reviewed.

I submit this contribution under the Apache-2.0 license.