refactor: rename public routes and templates to platform

Complete the public -> platform naming migration across the codebase.
This aligns with the naming convention where "platform" refers to
the marketing/public-facing pages of the platform itself.

Changes:
- Update all imports from public to platform modules
- Update template references from public/ to platform/
- Update route registrations to use platform prefix
- Update documentation to reflect new naming
- Update test files for platform API endpoints

Files affected:
- app/api/main.py - router imports
- app/modules/*/routes/*/platform.py - route definitions
- app/modules/*/templates/*/platform/ - template files
- app/modules/routes.py - route discovery
- docs/* - documentation updates
- tests/integration/api/v1/platform/ - test files

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/modules/billing/routes/api/platform.py

@@ -1,11 +1,11 @@
-# app/modules/billing/routes/api/public.py
+# app/modules/billing/routes/api/platform.py
 """
-Public pricing API endpoints.
+Platform pricing API endpoints.
 
 Provides subscription tier and add-on product information
 for the marketing homepage and signup flow.
 
-All endpoints are public (no authentication required).
+All endpoints are unauthenticated (no authentication required).
 """
 
 from fastapi import APIRouter, Depends

app/modules/billing/routes/pages/platform.py

@@ -1,8 +1,8 @@
-# app/modules/billing/routes/pages/public.py
+# app/modules/billing/routes/pages/platform.py
 """
-Billing Public Page Routes (HTML rendering).
+Billing Platform Page Routes (HTML rendering).
 
-Public (unauthenticated) pages for pricing and signup:
+Platform (unauthenticated) pages for pricing and signup:
 - Pricing page
 - Signup wizard
 - Signup success
@@ -14,7 +14,7 @@ from sqlalchemy.orm import Session
 
 from app.core.database import get_db
 from app.modules.billing.models import TIER_LIMITS, TierCode
-from app.modules.core.utils.page_context import get_public_context
+from app.modules.core.utils.page_context import get_platform_context
 from app.templates_config import templates
 
 router = APIRouter()
@@ -57,12 +57,12 @@ async def pricing_page(
     """
     Standalone pricing page with detailed tier comparison.
     """
-    context = get_public_context(request, db)
+    context = get_platform_context(request, db)
     context["tiers"] = _get_tiers_data()
     context["page_title"] = "Pricing"
 
     return templates.TemplateResponse(
-        "billing/public/pricing.html",
+        "billing/platform/pricing.html",
         context,
     )
 
@@ -86,14 +86,14 @@ async def signup_page(
     - tier: Pre-selected tier code
     - annual: Pre-select annual billing
     """
-    context = get_public_context(request, db)
+    context = get_platform_context(request, db)
     context["page_title"] = "Start Your Free Trial"
     context["selected_tier"] = tier
     context["is_annual"] = annual
     context["tiers"] = _get_tiers_data()
 
     return templates.TemplateResponse(
-        "billing/public/signup.html",
+        "billing/platform/signup.html",
         context,
     )
 
@@ -111,11 +111,11 @@ async def signup_success_page(
 
     Shown after successful account creation.
     """
-    context = get_public_context(request, db)
+    context = get_platform_context(request, db)
     context["page_title"] = "Welcome to Wizamart!"
     context["vendor_code"] = vendor_code
 
     return templates.TemplateResponse(
-        "billing/public/signup-success.html",
+        "billing/platform/signup-success.html",
         context,
     )

app/modules/billing/templates/billing/platform/pricing.html

@@ -1,6 +1,6 @@
 {# app/templates/platform/pricing.html #}
 {# Standalone Pricing Page #}
-{% extends "public/base.html" %}
+{% extends "platform/base.html" %}
 
 {% block title %}{{ _("cms.platform.pricing.title") }} - Wizamart{% endblock %}
 

app/modules/billing/templates/billing/platform/signup-success.html

@@ -1,6 +1,6 @@
 {# app/templates/platform/signup-success.html #}
 {# Signup Success Page #}
-{% extends "public/base.html" %}
+{% extends "platform/base.html" %}
 
 {% block title %}{{ _("cms.platform.success.title") }}{% endblock %}
 

app/modules/billing/templates/billing/platform/signup.html

@@ -1,6 +1,6 @@
 {# app/templates/platform/signup.html #}
 {# Multi-step Signup Wizard #}
-{% extends "public/base.html" %}
+{% extends "platform/base.html" %}
 
 {% block title %}Start Your Free Trial - Wizamart{% endblock %}
 
@@ -321,7 +321,7 @@ function signupWizard() {
         async startSignup() {
             this.loading = true;
             try {
-                const response = await fetch('/api/v1/public/signup/start', {
+                const response = await fetch('/api/v1/platform/signup/start', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     body: JSON.stringify({
@@ -352,7 +352,7 @@ function signupWizard() {
 
                 try {
                     // First lookup the vendor
-                    const lookupResponse = await fetch('/api/v1/public/letzshop-vendors/lookup', {
+                    const lookupResponse = await fetch('/api/v1/platform/letzshop-vendors/lookup', {
                         method: 'POST',
                         headers: { 'Content-Type': 'application/json' },
                         body: JSON.stringify({ url: this.letzshopUrl })
@@ -364,7 +364,7 @@ function signupWizard() {
                         this.letzshopVendor = lookupData.vendor;
 
                         // Claim the vendor
-                        const claimResponse = await fetch('/api/v1/public/signup/claim-vendor', {
+                        const claimResponse = await fetch('/api/v1/platform/signup/claim-vendor', {
                             method: 'POST',
                             headers: { 'Content-Type': 'application/json' },
                             body: JSON.stringify({
@@ -411,7 +411,7 @@ function signupWizard() {
             this.accountError = null;
 
             try {
-                const response = await fetch('/api/v1/public/signup/create-account', {
+                const response = await fetch('/api/v1/platform/signup/create-account', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     body: JSON.stringify({
@@ -461,7 +461,7 @@ function signupWizard() {
 
             // Get SetupIntent
             try {
-                const response = await fetch('/api/v1/public/signup/setup-payment', {
+                const response = await fetch('/api/v1/platform/signup/setup-payment', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     body: JSON.stringify({ session_id: this.sessionId })
@@ -500,7 +500,7 @@ function signupWizard() {
                 }
 
                 // Complete signup
-                const response = await fetch('/api/v1/public/signup/complete', {
+                const response = await fetch('/api/v1/platform/signup/complete', {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
                     body: JSON.stringify({