refactor: standardize level names across all roles (#195 phase 1)

Rename levels to use consistent industry-standard terminology:
- dev: medior → mid
- qa: reviewer → mid, tester → junior, add senior level
- architect: opus → senior, sonnet → junior

Add backward-compatible migration for projects.json and openclaw.json
config via level aliases in selectors and projects parser.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/services/tick.ts

@@ -48,7 +48,7 @@ export const PRIORITY_ORDER: StateLabel[] = getAllQueueLabels(DEFAULT_WORKFLOW);
 export function detectLevelFromLabels(labels: string[]): string | null {
   const lower = labels.map((l) => l.toLowerCase());
 
-  // Match role.level labels (e.g., "dev.senior", "qa.reviewer", "architect.opus")
+  // Match role.level labels (e.g., "dev.senior", "qa.mid", "architect.junior")
   for (const l of lower) {
     const dot = l.indexOf(".");
     if (dot === -1) continue;