Add build fallback, manual installation, and config sync

[vncntt]

Summary

• Add fallback to existing Docker images when devcontainer build fails
• Automatically install Claude if not found in container
• Sync Claude config (settings, plugins) from host to container

Problem

1. Build failures: The devcontainer CLI's --additional-features generates a Dockerfile-with-features that breaks SSH agent forwarding. This causes builds to fail for repos with private git dependencies.

2. Cached images: When using cached images, the claude-code feature isn't applied, so Claude isn't installed.

3. Config not syncing: The claude-config-mount feature doesn't work when features aren't applied. User settings like model: opus aren't transferred, and plugins don't work because their paths point to host locations.

Changes

Build failure fallback

• Detect when devcontainer up fails
• Find existing Docker image for the workspace (named vsc-<workspace>-*)
• Start container directly from existing image with workspace mounted

Manual Claude installation

• After container starts, check if Claude is available
• If not found, install via curl -fsSL https://claude.ai/install.sh | bash

Config sync

• Copy ~/.claude.json (authentication state)
• Copy ~/.claude/settings.json (user preferences)
• Copy plugins with path translation:
  • installed_plugins.json: Replace host paths with container paths
  • known_marketplaces.json: Replace host paths with container paths
  • Copy marketplaces/ and cache/ directories
• Fix permissions after docker cp (files are copied as root)

PATH handling

• Check both PATH and ~/.local/bin for Claude detection
• Launch claude with PATH including ~/.local/bin

Test plan

• Test on a devcontainer that fails to build (SSH issues)
• Verify fallback to existing image works
• Test on a devcontainer without Claude installed
• Verify config sync transfers settings (e.g., model: opus is preserved)
• Verify plugins work in container

Note

This PR includes PATH handling changes that overlap with PR #1. If PR #1 is merged first, this PR will need rebasing. Alternatively, this PR can be merged independently as it includes all necessary fixes.

🤖 Generated with Claude Code

[vncntt]

Code Review

Found 2 critical issues that need to be fixed before merging:

Issue 1: Missing --additional-features in start_devcontainer() (Bug)

The refactored start_devcontainer() function does not include --additional-features "$ADDITIONAL_FEATURES", meaning the Claude Code feature and config mount feature will never be installed via devcontainer features.

Location: bin/ccind L175-183

Current code:

start_devcontainer() {
    if [ "$REBUILD" = true ]; then
        echo_info "Starting devcontainer (forcing rebuild)..."
        devcontainer up --workspace-folder "$WORKSPACE" --remove-existing-container 2>&1
    else
        echo_info "Starting devcontainer..."
        devcontainer up --workspace-folder "$WORKSPACE" 2>&1
    fi
}

Fix: Add --additional-features "$ADDITIONAL_FEATURES" to both devcontainer up calls:

start_devcontainer() {
    if [ "$REBUILD" = true ]; then
        echo_info "Starting devcontainer (forcing rebuild)..."
        devcontainer up --workspace-folder "$WORKSPACE" --remove-existing-container --additional-features "$ADDITIONAL_FEATURES" 2>&1
    else
        echo_info "Starting devcontainer..."
        devcontainer up --workspace-folder "$WORKSPACE" --additional-features "$ADDITIONAL_FEATURES" 2>&1
    fi
}

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Issue 2: Version mismatch - referencing non-existent version (CLAUDE.md compliance)

The PR references claude-config-mount:0.1.6 in bin/ccind but the actual version in src/claude-config-mount/devcontainer-feature.json is 0.1.5. This will cause runtime failures when users try to pull a version that doesn't exist.

Location: bin/ccind L48

Fix: Update src/claude-config-mount/devcontainer-feature.json to bump version from 0.1.5 to 0.1.6.

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Checked for bugs and CLAUDE.md compliance.