docs: fix quick-start learning path links, update remaining internal cross-references

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

content/docs/getting-started/quick-start.mdx

@@ -96,27 +96,27 @@ Follow these guides in order for the best experience:
 <Cards>
   <Card
     title="1. Data Modeling"
-    href="./data-modeling"
+    href="/docs/guides/data-modeling"
     description="Design objects, fields, relationships, and validation rules. The foundation of every app."
   />
   <Card
     title="2. Business Logic"
-    href="./business-logic"
+    href="/docs/guides/business-logic"
     description="Implement workflows, approval flows, triggers, and formulas to automate business processes."
   />
   <Card
     title="3. Security Model"
-    href="./security"
+    href="/docs/guides/security"
     description="Configure profiles, permissions, sharing rules, and row-level security for enterprise-grade access control."
   />
   <Card
     title="4. AI Capabilities"
-    href="./ai-capabilities"
+    href="/docs/guides/ai-capabilities"
     description="Add AI agents, RAG pipelines, natural language queries, and predictive analytics."
   />
   <Card
     title="5. Development Standards"
-    href="./standards"
+    href="/docs/guides/standards"
     description="Naming conventions, project structure, testing strategies, and best practices."
   />
 </Cards>