v1.3.0 Workstream C — devtools (Memory Compare) + menu/Settings UX + auto-save

[doublegate]

v1.3.0 Workstream C — developer tooling + menu/Settings UX overhaul

Additive, native + UI only; no determinism surface (AccuracyCoin / oracle untouched).

Memory Compare panel (C3)

A cheat-hunt panel: snapshot the 2 KB work RAM and filter by changed / unchanged /
increased / decreased / equals across snapshots (the classic Cheat Engine workflow).
Read-only via cpu_bus_peek; integrity-guarded and RA-hardcore-gated like the
existing cheat tooling. New ChipPanel::MemoryCompare.

Menu-bar reorganization

• Top-level order is now File / Emulation / View / Tools / Debug / Help.
• File: added Close ROM; grouped all save-state actions under a Save States
  submenu (Save/Load State, Active Slot, Save-/Load-to-Slot, Manage States).
• Relocations: Swap Disk Side File → Emulation; NSF Player Debug → Tools;
  Performance Monitor Tools → Debug; the standalone "Mod" menu folded into a
  Tools HD Pack submenu (still hd-pack-feature + native-gated).
• Removed the redundant debugger checkbox toolbar (the menu bar already surfaces
  every panel).

Settings window

• New dedicated Shaders tab (the composable shader stack, split out of Video);
  "Advanced" renamed Emulation (run-ahead + rewind).
• Auto-save: the window snapshots the config each frame and persists on any
  change, so every setting in every tab is sticky (per-control save_config calls
  kept as a redundant backstop).

egui-0.34 menu close behavior (BUG-3)

Documented the egui-0.34 close model (default CloseOnClick, gated by egui's
deepest-submenu tracking) in ui_shell::menu_bar. The "menu lingers until several
clicks" report needs an on-device repro to pin the exact MenuState trigger and is
not changed blind (a wrong change would regress menu selection).

Gates

cargo fmt --check; clippy -D warnings (default + retroachievements +
scripting,hd-pack + both wasm flavours); markdownlint. Docs (docs/frontend.md)
and CHANGELOG.md [Unreleased] updated.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[gemini-code-assist]

Code Review

This pull request introduces a new Memory Compare (cheat-hunt) debugger panel, reorganizes the menu bar layout, adds a feature to close the currently loaded ROM, splits the shader stack into its own Settings tab, and implements auto-saving for settings. The reviewer provided several constructive suggestions: clearing additional staging buffers in close_rom to prevent stale state, optimizing the memory search apply function by avoiding redundant cpu_bus_peek calls, resolving inconsistent radix parsing for bare numbers in parse_byte, and avoiding per-frame allocations caused by cloning the entire Config structure while the Settings window is open.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

In close_rom, while self.present_staging is cleared, other staging buffers like self.present_index_staging (and self.present_hd_tiles / self.present_chr_snapshot if the hd-pack feature is enabled) are not cleared. To prevent stale state from lingering and to free up allocated memory when no ROM is loaded, these buffers should also be cleared.

fn close_rom(&mut self) {
        {
            let mut guard = self.emu.lock();
            let emu = &mut *guard;
            emu.nes = None;
            emu.perf.clear();
            emu.present_fb.clear();
            emu.audio_buf.clear();
            emu.next_frame_time = None;
        }
        // Stop the dedicated emulation thread from producing frames.
        #[cfg(all(not(target_arch = 

[gemini-code-assist]

Instead of calling cpu_bus_peek individually for each candidate (up to 2048 times) and then calling snapshot (which reads all 2048 bytes again), you can take the snapshot once at the beginning of apply. This avoids redundant cpu_bus_peek calls and improves efficiency.

    fn apply(&mut self, nes: &mut Nes) {
        let (Some(base), Some(cands)) = (self.baseline.as_ref(), self.candidates.as_mut()) else {
            return;
        };
        let cur_ram = snapshot(nes);
        let eq = parse_byte(&self.eq_text).unwrap_or(0);
        let filter = self.filter;
        cands.retain(|&addr| {
            let cur = cur_ram[addr as usize];
            filter.matches(base[addr as usize], cur, eq)
        });
        self.baseline = Some(cur_ram);
        self.steps += 1;
    }

[gemini-code-assist]

The parse_byte function has inconsistent parsing behavior for bare numbers (without $ or 0x prefixes). A bare input like "10" is parsed as decimal 10 because t.parse::<u8>() succeeds first, whereas "1A" is parsed as hex 26 (0x1A) via the fallback. This means the radix of bare inputs implicitly changes depending on whether they contain non-decimal hex characters (A-F). It is recommended to either treat all bare inputs consistently (e.g., always decimal, or always hex) or remove the bare hex fallback entirely to enforce explicit prefixes.

[gemini-code-assist]

Cloning the entire Config structure (which contains heap-allocated Vecs, Strings, and HashMaps) on every single frame while the Settings window is open introduces unnecessary allocation and CPU overhead. Since this project prioritizes high-performance and avoiding frame-rate stutter, we should avoid per-frame allocations. Consider only performing the clone/comparison when there is active user interaction in the settings window (e.g., ui.ctx().input(|i| i.pointer.any_down() || !i.keys_down.is_empty())), or detecting changes via state.apply.any().