Fix doubled colored output in dcat/dgrep by removing server-side coloring

Server should never send colored output - all colorization should happen
on the client side. This fix removes the colorization logic from the
server-side processors (catprocessor.go and grepprocessor.go).

Changes:
- Remove brush.Colorfy() calls from server-side processors
- Remove color-related imports and fields
- Update dlog.Raw() documentation to reflect server sends plain output
- Client-side coloring remains intact via dlog.Raw()

This ensures proper separation of concerns and prevents doubled ANSI
escape sequences in the output.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

3 files changed, 9 insertions, 50 deletions

diff --git a/internal/io/dlog/dlog.go b/internal/io/dlog/dlog.go
index 5bb6445..044624e 100644
--- a/internal/io/dlog/dlog.go
+++ b/internal/io/dlog/dlog.go
@@ -238,6 +238,8 @@ func (d *DLog) Devel(args ...interface{}) string {
 }
 
 // Raw message logging.
+// Raw logs messages from the server without the standard log formatting.
+// Since server never sends colored output, client handles all colorization.
 func (d *DLog) Raw(message string) string {
 	if d == nil {
 		return ""
diff --git a/internal/io/fs/catprocessor.go b/internal/io/fs/catprocessor.go
index b062c7f..0af8751 100644
--- a/internal/io/fs/catprocessor.go
+++ b/internal/io/fs/catprocessor.go
@@ -4,25 +4,20 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/mimecast/dtail/internal/color/brush"
 	"github.com/mimecast/dtail/internal/protocol"
 )
 
 // CatProcessor handles cat-style output
 type CatProcessor struct {
-	plain       bool
-	noColor     bool
-	hostname    string
-	isFirstLine bool
+	plain    bool
+	hostname string
 }
 
 // NewCatProcessor creates a new cat processor
 func NewCatProcessor(plain, noColor bool, hostname string) *CatProcessor {
 	return &CatProcessor{
-		plain:       plain,
-		noColor:     noColor,
-		hostname:    hostname,
-		isFirstLine: true,
+		plain:    plain,
+		hostname: hostname,
 	}
 }
 
@@ -69,29 +64,7 @@ func (cp *CatProcessor) ProcessLine(line []byte, lineNum int, filePath string, s
 		transmittedPerc, protocol.FieldDelimiter, count, protocol.FieldDelimiter,
 		sourceID, protocol.FieldDelimiter, string(line))
 
-	// Apply ANSI color formatting if not in plain mode and not noColor mode
-	if !cp.plain && !cp.noColor {
-		colorized := brush.Colorfy(protocolLine)
-
-		// Add color reset prefix for all lines except the first
-		var result []byte
-		if cp.isFirstLine {
-			cp.isFirstLine = false
-			result = make([]byte, len(colorized)+1)
-			copy(result, colorized)
-			result[len(colorized)] = '\n'
-		} else {
-			// Add color reset prefix: [39m[49m[49m[39m
-			colorResetPrefix := "\x1b[39m\x1b[49m\x1b[49m\x1b[39m"
-			result = make([]byte, len(colorResetPrefix)+len(colorized)+1)
-			copy(result, colorResetPrefix)
-			copy(result[len(colorResetPrefix):], colorized)
-			result[len(colorResetPrefix)+len(colorized)] = '\n'
-		}
-		return result, true
-	}
-
-	// No color formatting
+	// Server should never send colored output - client handles all colorization
 	result := make([]byte, len(protocolLine)+1)
 	copy(result, protocolLine)
 	result[len(protocolLine)] = '\n'
@@ -100,10 +73,6 @@ func (cp *CatProcessor) ProcessLine(line []byte, lineNum int, filePath string, s
 }
 
 func (cp *CatProcessor) Flush() []byte {
-	// Add final color reset line to match original behavior (no trailing newline)
-	// Only in non-plain mode with colors enabled
-	if !cp.plain && !cp.noColor {
-		return []byte("\x1b[39m\x1b[49m\x1b[49m\x1b[39m")
-	}
+	// Server should not send color codes - client handles colorization
 	return nil
 }
diff --git a/internal/io/fs/grepprocessor.go b/internal/io/fs/grepprocessor.go
index 57c4c2f..c9d1d79 100644
--- a/internal/io/fs/grepprocessor.go
+++ b/internal/io/fs/grepprocessor.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/mimecast/dtail/internal/color/brush"
 	"github.com/mimecast/dtail/internal/protocol"
 	"github.com/mimecast/dtail/internal/regex"
 )
@@ -13,7 +12,6 @@ import (
 type GrepProcessor struct {
 	regex    regex.Regex
 	plain    bool
-	noColor  bool
 	hostname string
 
 	// Context handling
@@ -33,7 +31,6 @@ func NewGrepProcessor(re regex.Regex, plain, noColor bool, hostname string, befo
 	gp := &GrepProcessor{
 		regex:          re,
 		plain:          plain,
-		noColor:        noColor,
 		hostname:       hostname,
 		beforeContext:  beforeContext,
 		afterContext:   afterContext,
@@ -165,16 +162,7 @@ func (gp *GrepProcessor) formatLine(line []byte, lineNum int, filePath string, s
 		transmittedPerc, protocol.FieldDelimiter, count, protocol.FieldDelimiter,
 		sourceID, protocol.FieldDelimiter, string(line))
 
-	// Apply ANSI color formatting if not in plain mode and not noColor mode.
-	if !gp.plain && !gp.noColor {
-		colorized := brush.Colorfy(protocolLine)
-		result := make([]byte, len(colorized)+1)
-		copy(result, colorized)
-		result[len(colorized)] = '\n'
-		return result
-	}
-
-	// No color formatting
+	// Server should never send colored output - client handles all colorization
 	result := make([]byte, len(protocolLine)+1)
 	copy(result, protocolLine)
 	result[len(protocolLine)] = '\n'