fix(dash-tui): stop the Engines preview claiming "Lemonade — not installed"

[lide4144]

Problem

Fixes #366

The dashboard's Serving → Engines preview always rendered · Lemonade — not installed, on machines where Lemonade is installed and rocm engines list correctly reports note: Lemonade is ready on your AMD GPU.

crates/rocm-dash-tui/src/ui/tabs/pane.rs read GpuSystemInfo::lemond_version, but nothing in the codebase ever writes that field:

$ grep -rn "lemond_version" --include=*.rs . | grep -v tests/
crates/rocm-dash-core/src/metrics.rs:59:  pub lemond_version: Option<String>,   # declaration
crates/rocm-dash-daemon/src/demo.rs:557:  lemond_version: None,                # demo fixture
crates/rocm-dash-tui/src/ui/tabs/pane.rs:364: ...clone()                       # only reader

rocm-dash-collectors::AmdSmiCollector::system_info() → parse_system_info() builds GpuSystemInfo::default() and fills only rocm_version, driver_version, model, counts, partition modes and VRAM. So lemon.is_some() was statically false, mark(...) always drew the "off" glyph, and the format!("Lemonade {v}") arm was unreachable — the panel asserted a negative it had no data for, and pushed users into a no-op rocm engines install lemonade.

Change

Drops the false claim and renders Lemonade the way the adjacent vLLM line already does — "open to check", muted — since that branch was already honest about having no detection. Both engine lines now come from one loop.

// The daemon doesn't surface engine detection yet — `GpuSystemInfo`
// has no producer for `lemond_version`, so every value read here
// would be `None` no matter what is installed. Open the manager to
// check rather than claiming a status we don't have.
for engine in ["Lemonade", "vLLM"] { ... }

Before / after in the preview panel:

· Lemonade — not installed        · Lemonade — open to check
· vLLM — open to check            · vLLM — open to check

vLLM's rendering is byte-identical. mark() and info() stay in use by the ROCm/driver lines in the same function, so no other call sites changed.

Deliberately minimal: this stops the wrong statement without inventing a detection path. The real fix is to populate lemond_version in the collector (reusing the resolution rocm engines list already performs in engines/lemonade/src/lib.rs) so the panel can show Lemonade 11.5.1 — happy to do that as a follow-up if maintainers prefer it over the honest placeholder, but it means the dash collector learns about engine manifests, which felt like the wrong direction for a drive-by.

Left in place: the sibling fields llama_server_build, ccr_version, llamacpp_backend (metrics.rs:60-62) have the same declared-never-written shape. They're currently unread, so no other UI lies today; removing or wiring them up is a separate call.

Verification

• rustfmt --edition 2024 --check crates/rocm-dash-tui/src/ui/tabs/pane.rs → clean
• cargo check -p rocm-dash-tui --all-targets → finished, no warnings
• no test asserted on the removed string (grep -rn "not installed\|open to check\|lemond_version" crates/rocm-dash-tui matched only the lines changed here); pane.rs has no mod tests, so nothing to update
• the before rendering was reproduced against the live TUI on the reporter's machine; the after line reuses the vLLM line's own widgets and style

No test added: pane.rs has no test module, so asserting on live_lines() means building an AppState + Snapshot fixture from scratch in a file that deliberately has none — heavier than the 4-line change it would guard. Happy to add one if a maintainer wants it, ideally alongside whoever wires lemond_version up for real.

Note: this commit was authored through the GitHub createCommitOnBranch API (the same path .github/workflows/dependabot-manifests-commit.yml uses), so it is web-flow signed (verification.verified = true) and carries a Signed-off-by trailer — cargo xtask verify-commits --require-verified should pass. The author has no local signing key and the API token cannot register one.