fix: translate remaining Spanish text in RoadmapTab

Fixed untranslated text in:
- Dual Strategy explanation paragraph (used dangerouslySetInnerHTML for HTML content)
- Priority queues table headers (Top Queues, Queue, Vol/month, Red Flags, Potential)

Added translation keys:
- roadmap.dualStrategy.explanation (EN/ES)
- Using existing roadmap.table.* keys for headers

Build verified successfully

https://claude.ai/code/session_03272424-c661-4002-a75e-2f81579fdd6e

frontend/locales/en.json

@@ -819,6 +819,9 @@
       "executeWave12": "Execute Wave 1-2 sequentially",
       "executeWave12Rationale": "Mixed operation: {{automate}} Tier 1 queues, {{assist}} Tier 2, {{augment}} Tier 3, {{human}} Tier 4.",
       "executeWave12NextStep": "Start with FOUNDATION to eliminate red flags, followed by AUGMENT to raise scores. Initial investment: {{amount}}."
+    },
+    "dualStrategy": {
+      "explanation": "The Dual Strategy consists of executing two parallel work streams: <strong>Quick Win</strong> immediately automates the {{count}} ready queues (Tier AUTOMATE, {{pct}}% of volume), generating returns from the first month; while <strong>Foundation</strong> prepares the remaining {{remaining}}% of volume (Tiers ASSIST and AUGMENT) by standardizing processes and reducing variability to enable future automation. This approach maximizes time-to-value: Quick Win finances the transformation and generates organizational confidence, while Foundation progressively expands the scope of automation."
     }
   },
   "opportunities": {