feat: show container name in structured log output (#1452)

* feat: show container name in structured log output

Prepend a normalized container name prefix to each line in
ComposeService.streamLogs() so both the structured log viewer
and the raw terminal identify which container produced each entry.

- Backend: prepend displayName (normalized via normalizeContainerName)
  before LogFormatter.process() in sendOutput and flushBuffer.
- LogFormatter: refactor process() to handle both prefix-first and
  timestamp-first input orders via a while-loop; widen PREFIX_REGEX
  to accept dotted service names.
- Frontend: add containerName to LogRow, extract prefix in parseLine,
  render as an inline mono chip in the message column, and include
  the name in downloaded logs (omitting the bracket prefix when null).
- Tests: 14 new tests across log-formatter, compose-service streamLogs,
  and StructuredLogViewer chip rendering + download formatting.

* fix: guard LogFormatter loop to at most one prefix and one timestamp

The while-loop refactored for order-agnostic prefix/timestamp
parsing could continue matching beyond the intended single prefix
and timestamp. A log line like "redis | 2024-...Z api | started"
would falsely colorize "api |" as a second container prefix in
raw terminal output.

Add prefixFound/timestampFound boolean guards so the loop stops
after one prefix and one timestamp, regardless of input order.

* feat: per-service color alternation for log container chips

Add an Appearance setting that lets users switch between unified
cyan and per-service label-token colors for the container name chips
in the structured log viewer.

- Extract HUE_VARS and hashLabel() from NodeLabelPill into a shared
  utility at frontend/src/lib/label-colors.ts.
- Add useLogChipColorMode hook (browser-local localStorage,
  sencho.log-chip-color-mode key, unified by default).
- Add SegmentedControl in Settings > Appearance > Display.
- Apply inline label-token styles via style attribute in per-service
  mode; keep current text-brand/80 bg-brand/10 classes in unified mode.
- 14 new tests across label-colors, hook, and viewer chip rendering.

backend/src/services/ComposeService.ts

@@ -16,6 +16,7 @@ import { deriveStackExposure } from './preflight/exposure';
 
 import { isDebugEnabled } from '../utils/debug';
 import { getErrorMessage } from '../utils/errors';
+import { normalizeContainerName } from '../utils/log-parsing';
 import { describeSpawnError } from '../utils/spawnErrors';
 import { isPathWithinBase, isValidStackName } from '../utils/validation';
 import { authoredComposeFileArgs, authoredComposeEnvFileArgs } from '../utils/authoredComposeArgs';
@@ -553,7 +554,8 @@ export class ComposeService {
         };
 
         for (const container of containersToLog) {
-          const containerName = container.Names?.[0]?.replace(/^\//, '') || container.Id;
+          const rawName = container.Names?.[0]?.replace(/^\//, '') || container.Id;
+          const displayName = normalizeContainerName(rawName, stackName);
           activeProcesses++;
           let lineBuffer = '';
 
@@ -563,19 +565,19 @@ export class ComposeService {
               const lines = lineBuffer.split(/\r?\n/);
               lineBuffer = lines.pop() || '';
               for (const line of lines) {
-                ws.send(LogFormatter.process(line) + '\r\n');
+                ws.send(LogFormatter.process(`${displayName} | ${line}`) + '\r\n');
               }
             }
           };
 
           const flushBuffer = () => {
             if (lineBuffer && ws.readyState === WebSocket.OPEN) {
-              ws.send(LogFormatter.process(lineBuffer) + '\r\n');
+              ws.send(LogFormatter.process(`${displayName} | ${lineBuffer}`) + '\r\n');
               lineBuffer = '';
             }
           };
 
-          const child = spawn('docker', ['logs', '-f', '-t', '--tail', '100', containerName], {
+          const child = spawn('docker', ['logs', '-f', '-t', '--tail', '100', rawName], {
             env: {
               ...process.env,
               PATH: process.env.PATH || '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'

backend/src/services/LogFormatter.ts

@@ -13,7 +13,7 @@ export class LogFormatter {
     private static readonly TIMESTAMP_REGEX = /^(\d{4}-\d{2}-\d{2}[T\s]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}:\d{2})?\s*)/;
 
     // Matches docker-compose style prefix like "container-name  | " or "db-1 | "
-    private static readonly PREFIX_REGEX = /^([a-zA-Z0-9_-]+)(?:\s+\|\s+)/;
+    private static readonly PREFIX_REGEX = /^([a-zA-Z0-9_.-]+)(?:\s+\|\s+)/;
 
     // Level regexes (case insensitive for matching, but we check raw string for precise targeting if needed)
     private static readonly ERROR_REGEX = /\b(ERROR|ERR|Exception|Fatal)\b/i;
@@ -26,26 +26,43 @@ export class LogFormatter {
         let processedLine = line;
         let formatAccumulator = '';
 
-        // 1. Process Timestamp
-        const tsMatch = processedLine.match(LogFormatter.TIMESTAMP_REGEX);
-        if (tsMatch) {
-            const ts = tsMatch[1];
-            formatAccumulator += `${LogFormatter.GRAY}${ts}${LogFormatter.RESET}`;
-            processedLine = processedLine.slice(ts.length);
+        // 1. Process at most one container-name prefix and one Docker
+        // timestamp in arrival order. Each regex is anchored at ^ and
+        // strips its match from the remainder. The prefixFound /
+        // timestampFound guards prevent false matches on legitimate
+        // log bodies that happen to contain "word | " later in the line.
+        let changed = true;
+        let prefixFound = false;
+        let timestampFound = false;
+        while (changed) {
+            changed = false;
+
+            if (!prefixFound) {
+                const prefixMatch = processedLine.match(LogFormatter.PREFIX_REGEX);
+                if (prefixMatch) {
+                    const pfxMatchStr = prefixMatch[0]; // e.g. "redis | "
+                    const name = prefixMatch[1];
+                    const restOfPrefix = pfxMatchStr.slice(name.length); // e.g. " | "
+                    formatAccumulator += `${LogFormatter.CYAN}${name}${LogFormatter.WHITE}${LogFormatter.RESET}${restOfPrefix}`;
+                    processedLine = processedLine.slice(pfxMatchStr.length);
+                    changed = true;
+                    prefixFound = true;
+                }
+            }
+
+            if (!timestampFound) {
+                const tsMatch = processedLine.match(LogFormatter.TIMESTAMP_REGEX);
+                if (tsMatch) {
+                    const ts = tsMatch[1];
+                    formatAccumulator += `${LogFormatter.GRAY}${ts}${LogFormatter.RESET}`;
+                    processedLine = processedLine.slice(ts.length);
+                    changed = true;
+                    timestampFound = true;
+                }
+            }
         }
 
-        // 2. Process Prefix
-        const prefixMatch = processedLine.match(LogFormatter.PREFIX_REGEX);
-        if (prefixMatch) {
-            const pfxMatchStr = prefixMatch[0]; // e.g. "container-name | "
-            const name = prefixMatch[1];
-            const restOfPrefix = pfxMatchStr.slice(name.length); // e.g. " | "
-
-            formatAccumulator += `${LogFormatter.CYAN}${name}${LogFormatter.WHITE}${LogFormatter.RESET}${restOfPrefix}`;
-            processedLine = processedLine.slice(pfxMatchStr.length);
-        }
-
-        // 3. Process Levels & JSON
+        // 2. Process Levels & JSON
         const trimmedLine = processedLine.trim();
 
         // Fast JSON Check (Starts with { and ends with })