Add build log file storage and download functionality

- Write deployment logs to files when deployment finishes (success or failure)
- Log files stored in DataDir/logs/<hostname>/<appname>/<appname>_<sha>_<timestamp>.log.txt
- Capture commit SHA for manual deploys by parsing git rev-parse HEAD after clone
- Add download endpoint for log files at /apps/{id}/deployments/{deploymentID}/download
- Add download link in deployment history view for finished deployments

internal/docker/client.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
@@ -417,7 +418,8 @@ type cloneConfig struct {
 
 // CloneResult contains the result of a git clone operation.
 type CloneResult struct {
-	Output string // Combined stdout/stderr from git clone
+	Output    string // Combined stdout/stderr from git clone
+	CommitSHA string // The HEAD commit SHA after clone/checkout
 }
 
 // CloneRepo clones a git repository using SSH and optionally checks out a specific commit.
@@ -590,16 +592,22 @@ func (c *Client) createGitContainer(
 	if cfg.commitSHA != "" {
 		// Clone without depth limit so we can checkout any commit, then checkout specific SHA
 		// Using sh -c to run multiple commands - need to clear entrypoint
+		// Output "COMMIT:<sha>" marker at end for parsing
 		script := fmt.Sprintf(
-			"git clone --branch %s %s /repo && cd /repo && git checkout %s",
+			"git clone --branch %s %s /repo && cd /repo && git checkout %s && echo COMMIT:$(git rev-parse HEAD)",
 			cfg.branch, cfg.repoURL, cfg.commitSHA,
 		)
 		entrypoint = []string{}
 		cmd = []string{"sh", "-c", script}
 	} else {
-		// Shallow clone of branch HEAD - use default git entrypoint
-		entrypoint = nil
-		cmd = []string{"clone", "--depth", "1", "--branch", cfg.branch, cfg.repoURL, "/repo"}
+		// Shallow clone of branch HEAD, then output commit SHA
+		// Using sh -c to run multiple commands
+		script := fmt.Sprintf(
+			"git clone --depth 1 --branch %s %s /repo && cd /repo && echo COMMIT:$(git rev-parse HEAD)",
+			cfg.branch, cfg.repoURL,
+		)
+		entrypoint = []string{}
+		cmd = []string{"sh", "-c", script}
 	}
 
 	// Use host paths for Docker bind mounts (Docker runs on the host, not in our container)
@@ -657,10 +665,31 @@ func (c *Client) runGitClone(ctx context.Context, containerID string) (*CloneRes
 			)
 		}
 
-		return &CloneResult{Output: logs}, nil
+		// Parse commit SHA from output (looks for "COMMIT:<sha>" line)
+		commitSHA := parseCommitSHA(logs)
+
+		return &CloneResult{Output: logs, CommitSHA: commitSHA}, nil
 	}
 }
 
+// commitMarker is the prefix used to identify commit SHA in clone output.
+const commitMarker = "COMMIT:"
+
+// parseCommitSHA extracts the commit SHA from git clone output.
+// It looks for a line starting with "COMMIT:" and returns the SHA after it.
+func parseCommitSHA(output string) string {
+	for line := range strings.SplitSeq(output, "\n") {
+		line = strings.TrimSpace(line)
+
+		sha, found := strings.CutPrefix(line, commitMarker)
+		if found {
+			return strings.TrimSpace(sha)
+		}
+	}
+
+	return ""
+}
+
 func (c *Client) connect(ctx context.Context) error {
 	opts := []client.Opt{
 		client.FromEnv,