DC-039: route all module file defaults through platformPaths.dataDir

Multiple modules derived file paths from __dirname, which is unstable in two
ways: (1) it moves whenever the file is reorganized under src/, and (2) it
points to the in-container source dir /app/src/<x> in production, which is
not bind-mounted, so writes would silently land in the image layer.

Affected modules (10 files): backup-manager, resource-monitor, update-manager,
docker-security, audit-logger, bundled-workflows, port-lock-manager, logging,
error-handler, license-keygen, plus crypto-utils and credential-manager which
already had multi-candidate resolvers but no centralised fallback.

Introduced platformPaths.dataDir (derived from SERVICES_FILE/CONFIG_FILE/
DNS_CREDENTIALS_FILE env vars when set, else path.dirname(servicesFile)) so
every module resolves the same canonical data directory. Each module now
fans the runtime files into the data dir while preserving per-file env-var
overrides for custom deployments.

Why a single resolver:
  - one place to swap the default path scheme in v2.x without chasing
    hardcoded __dirname joins
  - a single source-of-truth for tests, backup tools, and the soon-to-be
    added single-volume migration script
  - prevents the class of DC-033 (self-updater 0.0.0) bugs where __dirname
    drift in a subdirectory silently loses runtime state

Also fixed:
  - audit-logger: AUDIT_LOG_FILE default was /app/src/security/audit-log.json
    (writable in dev, image-layer in production). Now /app/data/audit-log.json
    via platformPaths.dataDir, matching logging.js's same file. Same physical
    path, no behavior change for callers that already set AUDIT_LOG_FILE.
  - logging.js: LOG_DIR was __dirname (src/utils/) — error.log and
    audit-log.json were being written into the source tree. Now
    platformPaths.dataDir, matching every other persistent file.
  - error-handler.js: ERROR_LOG_FILE hard-coded to __dirname/error.log
    (src/utilities/error.log), redundant with logging.js's own default.
    Now platformPaths.dataDir/error.log.
  - host-registry / event-store / event-workers: simplified the
    'platformPaths.dataDir || path.join(__dirname, ../../data)' pattern
    to just platformPaths.dataDir (the legacy fallback is no longer
    reachable — services.json lives at dataDir/services.json now).
  - public-routes-drift.test.js: added 'routes/security.js' to the
    direct-mount list so the /api/v1/security/events/ingest and
    /api/v1/security/events/batch entries in PUBLIC_ROUTES are
    recognized as mounted (was missing — fixed DC-044's drift-detection
    test gap).

Tests: 1214/1214 pass (0 new failures, 1 new test for the corrected route
mount detection path). ESLint: 146 warnings + 4 errors — same baseline as
HEAD (no new warnings or errors introduced; one pre-existing require-await
on readline was removed as a drive-by in event-workers.js since the module
uses line-level fs reads, not readline). Container config files like
audit-log.json, container-stats.json, and workflow-history.json still
exist on the running container's image layer — Docker will pick up the
new defaults on the next recreate (the update path already moves
services.json+config.json+credentials.json via the data bind mount).

dashcaddy-api/src/managers/credential-manager.js

@@ -9,24 +9,16 @@ const cryptoUtils = require('../security/crypto-utils');
 const lockfile = require('proper-lockfile');
 const fs = require('fs');
 const path = require('path');
+const platformPaths = require('../../platform-paths');
 
-// Resolve credentials file path — supports both standard install (/app/credentials.json)
-// and custom deployments with consolidated data directory (/app/data/credentials.json)
+// Resolve credentials alongside the canonical services/config state. This supports
+// both current /app/data mounts and legacy /app single-file mounts, and remains
+// stable if the module moves within src/.
 function resolveCredentialsFile() {
   if (process.env.CREDENTIALS_FILE) {
     return process.env.CREDENTIALS_FILE;
   }
-  const candidates = [
-    path.join(__dirname, 'credentials.json'),
-    path.join(__dirname, 'data', 'credentials.json'),
-  ];
-  for (const candidate of candidates) {
-    if (fs.existsSync(candidate)) {
-      return candidate;
-    }
-  }
-  // No existing file — return standard path so first store() creates it there
-  return candidates[0];
+  return path.join(platformPaths.dataDir, 'credentials.json');
 }
 
 const CREDENTIALS_FILE = resolveCredentialsFile();

dashcaddy-api/src/managers/license-keygen.js

@@ -15,9 +15,10 @@
 const crypto = require('crypto');
 const fs = require('fs');
 const path = require('path');
+const platformPaths = require('../../platform-paths');
 
 // Master secret file — lives only on admin machine, NEVER shipped
-const SECRET_FILE = path.join(__dirname, '.license-secret');
+const SECRET_FILE = process.env.LICENSE_SECRET_FILE || path.join(platformPaths.dataDir, '.license-secret');
 
 // License code format: DC-AAAAA-BBBBB-CCCCC-DDDDD
 // Encodes: version(4bit) + duration_days(12bit) + code_id(32bit) + created_ts(32bit) + hmac(48bit)
@@ -259,7 +260,7 @@ Valid durations: ${VALID_DURATIONS.join(', ')} days
   const count = countIndex !== -1 ? parseInt(args[countIndex + 1]) : 1;
 
   // Load or create counter file for auto-incrementing code IDs
-  const counterFile = path.join(__dirname, '.license-counter');
+  const counterFile = process.env.LICENSE_COUNTER_FILE || path.join(platformPaths.dataDir, '.license-counter');
   let startId;
   const startIdIndex = args.indexOf('--start-id');
   if (startIdIndex !== -1) {

dashcaddy-api/src/managers/port-lock-manager.js

@@ -7,8 +7,9 @@
 const fs = require('fs');
 const path = require('path');
 const lockfile = require('proper-lockfile');
+const platformPaths = require('../../platform-paths');
 
-const LOCK_DIR = path.join(__dirname, '.port-locks');
+const LOCK_DIR = process.env.PORT_LOCK_DIR || path.join(platformPaths.dataDir, '.port-locks');
 const LOCK_TIMEOUT = 120000; // 2 minutes
 const LOCK_STALE_THRESHOLD = 120000; // 2 minutes
 const LOCK_RETRY_OPTIONS = {

dashcaddy-api/src/managers/resource-monitor.js

@@ -8,15 +8,16 @@ const Docker = require('dockerode');
 const EventEmitter = require('events');
 const fs = require('fs');
 const path = require('path');
+const platformPaths = require('../../platform-paths');
 
 const docker = new Docker();
 
 // Configuration
-const STATS_FILE = process.env.STATS_FILE || path.join(__dirname, 'container-stats.json');
-const STATS_HOURLY_FILE = process.env.STATS_HOURLY_FILE || path.join(__dirname, 'container-stats-hourly.json');
-const STATS_DAILY_FILE = process.env.STATS_DAILY_FILE || path.join(__dirname, 'container-stats-daily.json');
-const ALERT_CONFIG_FILE = process.env.ALERT_CONFIG_FILE || path.join(__dirname, 'alert-config.json');
-const ALERT_HISTORY_FILE = process.env.ALERT_HISTORY_FILE || path.join(__dirname, 'alert-history.json');
+const STATS_FILE = process.env.STATS_FILE || path.join(platformPaths.dataDir, 'container-stats.json');
+const STATS_HOURLY_FILE = process.env.STATS_HOURLY_FILE || path.join(platformPaths.dataDir, 'container-stats-hourly.json');
+const STATS_DAILY_FILE = process.env.STATS_DAILY_FILE || path.join(platformPaths.dataDir, 'container-stats-daily.json');
+const ALERT_CONFIG_FILE = process.env.ALERT_CONFIG_FILE || path.join(platformPaths.dataDir, 'alert-config.json');
+const ALERT_HISTORY_FILE = process.env.ALERT_HISTORY_FILE || path.join(platformPaths.dataDir, 'alert-history.json');
 const STATS_RETENTION_HOURS = parseInt(process.env.STATS_RETENTION_HOURS || '168', 10); // 7 days raw
 const STATS_HOURLY_RETENTION_DAYS = parseInt(process.env.STATS_HOURLY_RETENTION_DAYS || '30', 10); // 30 days hourly
 const STATS_DAILY_RETENTION_DAYS = parseInt(process.env.STATS_DAILY_RETENTION_DAYS || '365', 10); // 365 days daily

dashcaddy-api/src/managers/update-manager.js

@@ -9,11 +9,12 @@ const EventEmitter = require('events');
 const fs = require('fs');
 const path = require('path');
 const https = require('https');
+const platformPaths = require('../../platform-paths');
 
 const docker = new Docker();
 
-const UPDATE_CONFIG_FILE = process.env.UPDATE_CONFIG_FILE || path.join(__dirname, 'update-config.json');
-const UPDATE_HISTORY_FILE = process.env.UPDATE_HISTORY_FILE || path.join(__dirname, 'update-history.json');
+const UPDATE_CONFIG_FILE = process.env.UPDATE_CONFIG_FILE || path.join(platformPaths.dataDir, 'update-config.json');
+const UPDATE_HISTORY_FILE = process.env.UPDATE_HISTORY_FILE || path.join(platformPaths.dataDir, 'update-history.json');
 const CHECK_INTERVAL = parseInt(process.env.UPDATE_CHECK_INTERVAL || '3600000', 10); // 1 hour
 
 class UpdateManager extends EventEmitter {