refactor(backend): sanitize user input before logging to close CRLF injection (#807)

* refactor(backend): sanitize user input before logging to close CRLF injection

Adds a small sanitizeForLog helper that strips CR, LF, tab, and ASCII
control characters (0x00-0x1F, 0x7F) from a value before it is embedded
in a console.log/warn/error/debug call. Wraps every call site where a
user-controlled value (req.params, req.body, req.query, or a value
derived from them) flows into a log message.

Closes the bulk of the open CodeQL alerts in this family:
- 96 js/log-injection
- 28 js/tainted-format-string

The helper is in backend/src/utils/safeLog.ts. Routes still pre-validate
input at the request boundary; this is the second line of defense and
gives static analyzers a sanitizer they can trace through. JSON
responses, Docker filter labels, and other non-log call sites are
intentionally left unwrapped.

* refactor(backend): printf-style format strings for tainted-log call sites

CodeQL's js/tainted-format-string rule flags template literals in the first
arg of console.X when any interpolated value is user-controlled, regardless
of whether each value is sanitized inline. The canonical mitigation is to
use a static format string and pass values as positional args.

Converts the 28 flagged template literals to printf-style ("%s") format
strings, with sanitizeForLog applied to each positional arg. Also fills in
the log-injection wraps on 9 sites where a user-controlled value was
missed in the first sweep (agents, fleet, gitSources, imageUpdates,
GitSourceService).

No behavior change at runtime. Node's util.format substitutes %s tokens
identically to template-literal interpolation.

* fix(backend): wrap nodeId/snapshotId in fleet restore debug log

CodeQL flagged the unwrapped numeric args even though they cannot
contain control chars in practice. Apply the sanitizer for taint-flow
recognition.

backend/src/routes/ssoConfig.ts

@@ -3,6 +3,7 @@ import { DatabaseService } from '../services/DatabaseService';
 import { SSOService, type SSOProviderConfig } from '../services/SSOService';
 import { requireAdmin, requireTierForSsoProvider } from '../middleware/tierGates';
 import { rejectApiTokenScope } from '../middleware/apiTokenScope';
+import { sanitizeForLog } from '../utils/safeLog';
 
 const VALID_SSO_PROVIDERS = ['ldap', 'oidc_google', 'oidc_github', 'oidc_okta', 'oidc_custom'] as const;
 const SSO_SCOPE_MESSAGE = 'API tokens cannot access SSO configuration.';
@@ -85,7 +86,7 @@ ssoConfigRouter.put('/:provider', (req: Request, res: Response): void => {
     }
 
     SSOService.getInstance().saveProviderConfig(config);
-    console.log(`[SSO] Config updated: ${provider} ${config.enabled ? 'enabled' : 'disabled'}`);
+    console.log(`[SSO] Config updated: ${sanitizeForLog(provider)} ${config.enabled ? 'enabled' : 'disabled'}`);
     res.json({ success: true, message: 'SSO configuration saved' });
   } catch (error) {
     console.error('[SSO] Failed to save SSO config:', error);
@@ -101,7 +102,7 @@ ssoConfigRouter.delete('/:provider', (req: Request, res: Response): void => {
   if (!requireTierForSsoProvider(provider, req, res)) return;
   try {
     SSOService.getInstance().deleteProviderConfig(provider);
-    console.log(`[SSO] Config deleted: ${provider}`);
+    console.log(`[SSO] Config deleted: ${sanitizeForLog(provider)}`);
     res.json({ success: true, message: 'SSO configuration deleted' });
   } catch (error) {
     console.error('[SSO] Failed to delete SSO config:', error);