fix(desktop): harden readiness and live WAL readback

[DTALEX66]

Summary

• harden Tauri Core readiness polling and HTTP response framing
• support HTTP/1.0 close, chunked bodies, raw-byte reads, and bounded timeout handling
• keep strict readiness identity validation
• use query-only live-WAL readback after research intake commits

Verification

• cargo fmt --all -- --check
• cargo test --lib — 14 passed
• tests/test_workspace_delivery_lifecycle.py — all matrix states covered
• targeted Workspace API/projection tests — 2 passed
• git diff --check

Evidence boundary

• current-tree local tests above are not a substitute for PR exact-head CI
• no release/tag mutation