build(pty): restore bundled ConPTY after rebuild

[janburzinski]

Description

• fullscreen tuis (openode,cc,amp,etc.) in terminals on win 10 used to get no mouse input, wheel scrolling or usable text selection
• conpty swallos mouse-mode/alt-screen requests and drops mouse reports
• local pty now spawn with node-pty useConptyDll:true, loading the bundled upt odate conpty
• use bundled conpty for windows ptys
• restore conpty files after native rebuilds

Screenshot/Recording (if applicable)

on windows:
https://cap.link/p11pxnh1aefg92x

Checklist

• I kept this PR small and focused
• I ran a self-review before opening this PR
• I ran the relevant local checks or explained why not
• I updated docs when behavior or setup changed
• I added or updated tests when behavior changed, or explained why not
• I only added comments where the logic is not obvious
• I used Conventional Commits for commit
  messages and, when possible, the PR title

[janburzinski]

@greptileai

[greptile-apps]

Greptile Summary

This PR fixes a long-standing Windows 10 regression where fullscreen TUIs (opencode, claude, amp, etc.) received no mouse input or scroll events because the OS in-box ConPTY silently swallowed mouse-mode DECSETs and SGR mouse reports. The fix opts node-pty into its bundled, up-to-date ConPTY dll (useConptyDll: true) and adds the plumbing to restore that dll after every electron-rebuild invocation, which wipes build/Release.

• conpty-dll.ts resolves and caches dll presence by mirroring node-pty's native-module search order, with an env-var escape hatch and a markConptyDllUnavailable seam for AV-quarantine fallback.
• local-pty.ts forwards the resolved flag to nodePty.spawn and retries with the in-box ConPTY if the bundled dll fails to load, permanently disabling it only when the fallback succeeds.
• copy-conpty-dll.ts (and its callers in postinstall.ts, rebuild-native.ts, package.json, and CI) restores the dll files after every node-gyp rebuild wipes them, with version-folder picking that validates all required files before selecting.

Confidence Score: 5/5

Safe to merge; the fallback to in-box ConPTY is well-guarded and the dll restore runs at all the right callsites.

The retry logic in spawnLocalPty is sound — markConptyDllUnavailable is only called when the in-box fallback succeeds, so command-level failures (bad cwd, missing binary) don't permanently disable the bundled dll. The copy script validates all required files before picking a version folder, handles the no-rebuilt-output case cleanly, and is tested against the key edge cases. The change is Windows-only at runtime and no-ops silently on all other platforms.

No files require special attention; the most scrutiny-worthy path is the spawnLocalPty retry loop in local-pty.ts, which is covered by the new unit tests.

Important Files Changed

Filename	Overview
.github/workflows/windows-beta-build.yml	Fixes sqlite3→better-sqlite3 module name in electron-rebuild args and adds copy-conpty-dll step after native rebuild; straightforward CI plumbing.
apps/emdash-desktop/scripts/copy-conpty-dll.ts	New utility that restores the bundled ConPTY dll after electron-rebuild wipes build/Release; validates arch, checks all required files exist before picking a version folder, and handles platform/arch guards cleanly.
apps/emdash-desktop/scripts/copy-conpty-dll.test.ts	Comprehensive tests covering no-op on non-Windows, correct arch selection, missing output/source, incomplete version folders, and unsupported archs.
apps/emdash-desktop/scripts/postinstall.ts	Correctly gates the copyConptyDll call on !disablePty, mirroring the existing PTY rebuild guard; the call is a no-op off Windows.
apps/emdash-desktop/scripts/release/rebuild-native.ts	Correctly chains copyConptyDll after rebuild completes for the target arch; arch is already validated earlier in the script.
apps/emdash-desktop/src/main/core/pty/conpty-dll.ts	Well-designed module with proper memoization, escape hatch env var, test seams, and correct mirroring of node-pty's native module search order.
apps/emdash-desktop/src/main/core/pty/conpty-dll.test.ts	Tests cover platform guard, env-var override, rebuilt-vs-prebuilt dll path resolution, and the electron-rebuild wipe scenario.
apps/emdash-desktop/src/main/core/pty/local-pty.ts	Spawn logic cleanly delegates ConPTY selection and adds a resilient fallback; markConptyDllUnavailable is only called when the fallback succeeds.
apps/emdash-desktop/src/main/core/pty/local-pty.test.ts	New unit tests verify ConPTY flag forwarding, dll-failure retry, dual-failure error propagation, and no-retry when dll was not requested.
apps/emdash-desktop/src/main/core/pty/local-pty.integration.test.ts	New Windows-only integration test verifies mouse-mode and alt-screen DECSETs pass through the bundled ConPTY; correctly uses it.runIf to skip on non-Windows.
apps/emdash-desktop/package.json	Appends the copy-conpty-dll step to the rebuild script so the dll is restored after every manual pnpm run rebuild invocation.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[spawnLocalPty called] --> B[resolveUseConptyDll]
    B --> C{win32?}
    C -- No --> D[return false]
    C -- Yes --> E{EMDASH_DISABLE_CONPTY_DLL=1?}
    E -- Yes --> D
    E -- No --> F[conptyDllIsPresent - cached]
    F --> G{cachedPresence}
    G -- false --> D
    G -- true --> H[return true]
    D --> I[spawn with useConptyDll=false]
    H --> J[spawn with useConptyDll=true]
    J --> K{spawn throws?}
    K -- No --> L[return LocalPtySession]
    K -- Yes --> M[log warn]
    M --> N[retry spawn useConptyDll=false]
    N --> O{retry throws?}
    O -- No --> P[markConptyDllUnavailable]
    P --> Q[return LocalPtySession]
    O -- Yes --> R[throw spawnError]
    I --> S{spawn throws?}
    S -- No --> L
    S -- Yes --> T[throw spawnError]

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
flowchart TD
    A[spawnLocalPty called] --> B[resolveUseConptyDll]
    B --> C{win32?}
    C -- No --> D[return false]
    C -- Yes --> E{EMDASH_DISABLE_CONPTY_DLL=1?}
    E -- Yes --> D
    E -- No --> F[conptyDllIsPresent - cached]
    F --> G{cachedPresence}
    G -- false --> D
    G -- true --> H[return true]
    D --> I[spawn with useConptyDll=false]
    H --> J[spawn with useConptyDll=true]
    J --> K{spawn throws?}
    K -- No --> L[return LocalPtySession]
    K -- Yes --> M[log warn]
    M --> N[retry spawn useConptyDll=false]
    N --> O{retry throws?}
    O -- No --> P[markConptyDllUnavailable]
    P --> Q[return LocalPtySession]
    O -- Yes --> R[throw spawnError]
    I --> S{spawn throws?}
    S -- No --> L
    S -- Yes --> T[throw spawnError]

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_{Reviews (3): Last reviewed commit: "fix(pty): select complete bundled ConPTY..." | Re-trigger Greptile}

[janburzinski]

@greptileai