feat: enhance search with date-prioritized year filtering and true exact matching

Improve media item search functionality with two key enhancements:

1. Date-prioritized year filtering:
   - Prioritize date_published over copyright_year for year range queries
   - Fall back to copyright_year when date_published is NULL
   - Extract year from date_published timestamp for comparison

2. True exact search matching:
   - Replace ILIKE pattern matching with exact equality for quoted queries
   - Use search_query directly instead of wildcard pattern for exact matches
   - Remove SearchPattern parameter and related wildcard logic
   - Add COALESCE handling for author/series NULL values in exact matches

These changes make year filtering more accurate with published dates
and provide genuine exact matching when users wrap queries in quotes.

Refs internal/database/queries/queries.sql:475, internal/services/search.go:62

internal/database/queries.sql.go

@@ -7259,9 +7259,17 @@ WHERE COALESCE(lv.is_visible, true) = true
     SELECT 1 FROM unnest(mi.tags_search) AS tag
     WHERE word_similarity($7, tag) > 0.3
   ))
-  -- Year range (exact)
-  AND ($8 = 0 OR mi.copyright_year >= $8)
-  AND ($9 = 0 OR mi.copyright_year <= $9)
+  -- Year range (exact) - prioritize date_published, fallback to copyright_year
+  AND (
+    $8 = 0 OR
+    EXTRACT(YEAR FROM mi.date_published) >= $8 OR
+    (mi.date_published IS NULL AND mi.copyright_year >= $8)
+  )
+  AND (
+    $9 = 0 OR
+    EXTRACT(YEAR FROM mi.date_published) <= $9 OR
+    (mi.date_published IS NULL AND mi.copyright_year <= $9)
+  )
   -- Boolean (exact)
   AND ($10 = false OR mi.cover_image_path IS NOT NULL)
   -- Search query (fuzzy or exact based on quotes)
@@ -7284,12 +7292,21 @@ WHERE COALESCE(lv.is_visible, true) = true
       )
     ) OR
     -- Exact search (with quotes)
+    -- Keeping old pattern commented out in case we want wildcard exact back. See search.go line 62
+    -- sqlc.narg('is_exact_search') = true AND (
+    --   mi.title ILIKE sqlc.narg('search_pattern') OR
+    --   mi.author ILIKE sqlc.narg('search_pattern') OR
+    --   mi.series ILIKE sqlc.narg('search_pattern') OR
+    --   sqlc.narg('search_pattern') = ANY(mi.tags_search) OR
+    --   sqlc.narg('search_pattern') = ANY(mi.contributors_search)
+    -- )
+    -- Exact search (with quotes) - true exact match, not substring
     $12 = true AND (
-      mi.title ILIKE $13 OR
-      mi.author ILIKE $13 OR
-      mi.series ILIKE $13 OR
-      $13 = ANY(mi.tags_search) OR
-      $13 = ANY(mi.contributors_search)
+        mi.title = $11 OR
+        COALESCE(mi.author, '') = $11 OR
+        COALESCE(mi.series, '') = $11 OR
+        $11 = ANY(mi.tags_search) OR
+        $11 = ANY(mi.contributors_search)
     )
   )
 ORDER BY
@@ -7313,40 +7330,40 @@ ORDER BY
   END DESC,
   -- Secondary sort: user-specified sort parameter
   CASE
-    WHEN $14 = 'title ASC' THEN mi.title
+    WHEN $13 = 'title ASC' THEN mi.title
     ELSE ''
   END ASC,
   CASE
-    WHEN $14 = 'title DESC' THEN mi.title
+    WHEN $13 = 'title DESC' THEN mi.title
     ELSE ''
   END DESC,
   CASE
-    WHEN $14 = 'author ASC' THEN COALESCE(mi.author, '')
+    WHEN $13 = 'author ASC' THEN COALESCE(mi.author, '')
     ELSE ''
   END ASC,
   CASE
-    WHEN $14 = 'author DESC' THEN COALESCE(mi.author, '')
+    WHEN $13 = 'author DESC' THEN COALESCE(mi.author, '')
     ELSE ''
   END DESC,
   CASE
-    WHEN $14 = 'created_at ASC' THEN mi.created_at
+    WHEN $13 = 'created_at ASC' THEN mi.created_at
     ELSE '1970-01-01'::timestamp
   END ASC,
   CASE
-    WHEN $14 = 'created_at DESC' THEN mi.created_at
+    WHEN $13 = 'created_at DESC' THEN mi.created_at
     ELSE '1970-01-01'::timestamp
   END DESC,
   CASE
-    WHEN $14 = 'page_count ASC' THEN COALESCE(mi.page_count::text, '0')
+    WHEN $13 = 'page_count ASC' THEN COALESCE(mi.page_count::text, '0')
     ELSE ''
   END ASC,
   CASE
-    WHEN $14 = 'page_count DESC' THEN COALESCE(mi.page_count::text, '0')
+    WHEN $13 = 'page_count DESC' THEN COALESCE(mi.page_count::text, '0')
     ELSE ''
   END DESC,
   -- Tertiary sort: title (default fallback)
   mi.title ASC
-LIMIT $16 OFFSET $15
+LIMIT $15 OFFSET $14
 `
 
 type SearchMediaItemsUnifiedParams struct {
@@ -7362,7 +7379,6 @@ type SearchMediaItemsUnifiedParams struct {
 	HasCover       interface{} `db:"has_cover" json:"has_cover"`
 	SearchQuery    interface{} `db:"search_query" json:"search_query"`
 	IsExactSearch  interface{} `db:"is_exact_search" json:"is_exact_search"`
-	SearchPattern  pgtype.Text `db:"search_pattern" json:"search_pattern"`
 	Sort           interface{} `db:"sort" json:"sort"`
 	Offset         pgtype.Int4 `db:"offset" json:"offset"`
 	Limit          pgtype.Int4 `db:"limit" json:"limit"`
@@ -7431,7 +7447,6 @@ func (q *Queries) SearchMediaItemsUnified(ctx context.Context, arg SearchMediaIt
 		arg.HasCover,
 		arg.SearchQuery,
 		arg.IsExactSearch,
-		arg.SearchPattern,
 		arg.Sort,
 		arg.Offset,
 		arg.Limit,