Migrate from Gin to Echo framework and add comprehensive integration tests

Major changes:
- Migrate all handlers from Gin to Echo framework
- Add new apperrors, echohelpers, and validator packages
- Update middleware for Echo compatibility
- Add ArchivedHandler to task categorization chain (archived tasks go to cancelled_tasks column)
- Add 6 new integration tests:
  - RecurringTaskLifecycle: NextDueDate advancement for weekly/monthly tasks
  - MultiUserSharing: Complex sharing with user removal
  - TaskStateTransitions: All state transitions and kanban column changes
  - DateBoundaryEdgeCases: Threshold boundary testing
  - CascadeOperations: Residence deletion cascade effects
  - MultiUserOperations: Shared residence collaboration
- Add single-purpose repository functions for kanban columns (GetOverdueTasks, GetDueSoonTasks, etc.)
- Fix RemoveUser route param mismatch (userId -> user_id)
- Fix determineExpectedColumn helper to correctly prioritize in_progress over overdue

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/handlers/static_data_handler.go

@@ -4,7 +4,7 @@ import (
 	"net/http"
 	"strings"
 
-	"github.com/gin-gonic/gin"
+	"github.com/labstack/echo/v4"
 	"github.com/redis/go-redis/v9"
 	"github.com/rs/zerolog/log"
 
@@ -51,20 +51,19 @@ func NewStaticDataHandler(
 
 // GetStaticData handles GET /api/static_data/
 // Returns all lookup/reference data in a single response with ETag support
-func (h *StaticDataHandler) GetStaticData(c *gin.Context) {
-	ctx := c.Request.Context()
+func (h *StaticDataHandler) GetStaticData(c echo.Context) error {
+	ctx := c.Request().Context()
 
 	// Check If-None-Match header for conditional request
 	// Strip W/ prefix if present (added by reverse proxy, but we store without it)
-	clientETag := strings.TrimPrefix(c.GetHeader("If-None-Match"), "W/")
+	clientETag := strings.TrimPrefix(c.Request().Header.Get("If-None-Match"), "W/")
 
 	// Try to get cached ETag first (fast path for 304 responses)
 	if h.cache != nil && clientETag != "" {
 		cachedETag, err := h.cache.GetSeededDataETag(ctx)
 		if err == nil && cachedETag == clientETag {
 			// Client has the latest data, return 304 Not Modified
-			c.Status(http.StatusNotModified)
-			return
+			return c.NoContent(http.StatusNotModified)
 		}
 	}
 
@@ -76,11 +75,10 @@ func (h *StaticDataHandler) GetStaticData(c *gin.Context) {
 			// Cache hit - get the ETag and return data
 			etag, etagErr := h.cache.GetSeededDataETag(ctx)
 			if etagErr == nil {
-				c.Header("ETag", etag)
-				c.Header("Cache-Control", "private, max-age=3600")
+				c.Response().Header().Set("ETag", etag)
+				c.Response().Header().Set("Cache-Control", "private, max-age=3600")
 			}
-			c.JSON(http.StatusOK, cachedData)
-			return
+			return c.JSON(http.StatusOK, cachedData)
 		} else if err != redis.Nil {
 			// Log cache error but continue to fetch from DB
 			log.Warn().Err(err).Msg("Failed to get cached seeded data")
@@ -90,38 +88,32 @@ func (h *StaticDataHandler) GetStaticData(c *gin.Context) {
 	// Cache miss - fetch all data from services
 	residenceTypes, err := h.residenceService.GetResidenceTypes()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_residence_types")})
-		return
+		return err
 	}
 
 	taskCategories, err := h.taskService.GetCategories()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_task_categories")})
-		return
+		return err
 	}
 
 	taskPriorities, err := h.taskService.GetPriorities()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_task_priorities")})
-		return
+		return err
 	}
 
 	taskFrequencies, err := h.taskService.GetFrequencies()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_task_frequencies")})
-		return
+		return err
 	}
 
 	contractorSpecialties, err := h.contractorService.GetSpecialties()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_contractor_specialties")})
-		return
+		return err
 	}
 
 	taskTemplates, err := h.taskTemplateService.GetGrouped()
 	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": i18n.LocalizedMessage(c, "error.failed_to_fetch_task_templates")})
-		return
+		return err
 	}
 
 	// Build response
@@ -140,19 +132,19 @@ func (h *StaticDataHandler) GetStaticData(c *gin.Context) {
 		if cacheErr != nil {
 			log.Warn().Err(cacheErr).Msg("Failed to cache seeded data")
 		} else {
-			c.Header("ETag", etag)
-			c.Header("Cache-Control", "private, max-age=3600")
+			c.Response().Header().Set("ETag", etag)
+			c.Response().Header().Set("Cache-Control", "private, max-age=3600")
 		}
 	}
 
-	c.JSON(http.StatusOK, seededData)
+	return c.JSON(http.StatusOK, seededData)
 }
 
 // RefreshStaticData handles POST /api/static_data/refresh/
 // This is a no-op since data is fetched fresh each time
 // Kept for API compatibility with mobile clients
-func (h *StaticDataHandler) RefreshStaticData(c *gin.Context) {
-	c.JSON(http.StatusOK, gin.H{
+func (h *StaticDataHandler) RefreshStaticData(c echo.Context) error {
+	return c.JSON(http.StatusOK, map[string]interface{}{
 		"message": i18n.LocalizedMessage(c, "message.static_data_refreshed"),
 		"status":  "success",
 	})