fix: fix terminal not opening in Docker and slim down Docker image

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -26,9 +26,6 @@ RUN apt-get update && apt-get install -y \
     curl \
     python3 \
     python3-pip \
-    gcc \
-    g++ \
-    make \
     && rm -rf /var/lib/apt/lists/*
 
 COPY --from=backend /app/src-tauri/target/release/codeg-server /usr/local/bin/codeg-server
@@ -38,6 +35,7 @@ ENV CODEG_STATIC_DIR=/app/web
 ENV CODEG_DATA_DIR=/data
 ENV CODEG_PORT=3080
 ENV CODEG_HOST=0.0.0.0
+ENV SHELL=/bin/bash
 
 EXPOSE 3080
 VOLUME /data

Dockerfile.ci

@@ -12,9 +12,6 @@ RUN apt-get update && apt-get install -y \
     curl \
     python3 \
     python3-pip \
-    gcc \
-    g++ \
-    make \
     && rm -rf /var/lib/apt/lists/*
 
 COPY dist/${TARGETARCH}/codeg-server /usr/local/bin/codeg-server
@@ -24,6 +21,7 @@ ENV CODEG_STATIC_DIR=/app/web
 ENV CODEG_DATA_DIR=/data
 ENV CODEG_PORT=3080
 ENV CODEG_HOST=0.0.0.0
+ENV SHELL=/bin/bash
 
 EXPOSE 3080
 VOLUME /data

src-tauri/src/terminal/manager.rs

@@ -44,7 +44,19 @@ fn resolve_shell() -> String {
     }
     #[cfg(not(target_os = "windows"))]
     {
-        std::env::var("SHELL").unwrap_or_else(|_| "/bin/zsh".to_string())
+        if let Ok(shell) = std::env::var("SHELL") {
+            let trimmed = shell.trim();
+            if !trimmed.is_empty() {
+                return trimmed.to_string();
+            }
+        }
+        // Try common shells in order of preference
+        for candidate in ["/bin/zsh", "/bin/bash", "/bin/sh"] {
+            if std::path::Path::new(candidate).exists() {
+                return candidate.to_string();
+            }
+        }
+        "/bin/sh".to_string()
     }
 }