Frontend overhaul: NetBox-style detail pages, selectable columns, data sources

- Cultivar/species detail pages rewritten with two-column card layout, attribute tables, em-dash placeholders
- Column toggle + per-page selector on all list pages (families, species, cultivars, suppliers)
- Species list: table/card view toggle with family, layer, N-fixer, uses columns
- Cultivar detail: supplier links with SKU/price/product URL, species info section
- Data sources page (/sources) with attribution for all 10 data sources
- Fixed Cultivar/Species structs with #[serde(default)] for API compatibility
- Added table_controls component (reusable column toggle + per-page selector)
- Removed max-width constraint on content area for full-width tables
- Fixed route conflicts: merged {slug}/{id} into single {ref} routes
- Removed PostgreSQL enum types (plant_layer, drought_tolerance, etc.) in favor of TEXT
- Fixed API per_page parameter support across all list endpoints

herbapi-api/migrations/002_create_species.sql

@@ -14,28 +14,28 @@ CREATE TABLE species (
     description       TEXT,
     soil_moisture     TEXT,
     drainage_requirement TEXT,
-    organic_matter_pct NUMERIC(5,2),
+    organic_matter_pct DOUBLE PRECISION,
     nitrogen_ppm      INTEGER,
     phosphorus_ppm    INTEGER,
     potassium_ppm     INTEGER,
-    boron_ppm         NUMERIC(8,2),
+    boron_ppm         DOUBLE PRECISION,
     calcium_ppm       INTEGER,
-    copper_ppm        NUMERIC(8,2),
-    iron_ppm          NUMERIC(8,2),
+    copper_ppm        DOUBLE PRECISION,
+    iron_ppm          DOUBLE PRECISION,
     magnesium_ppm     INTEGER,
-    manganese_ppm     NUMERIC(8,2),
-    molybdenum_ppm    NUMERIC(8,2),
+    manganese_ppm     DOUBLE PRECISION,
+    molybdenum_ppm    DOUBLE PRECISION,
     sulfur_ppm        INTEGER,
-    zinc_ppm          NUMERIC(8,2),
-    ph_min            NUMERIC(4,2),
-    ph_max            NUMERIC(4,2),
+    zinc_ppm          DOUBLE PRECISION,
+    ph_min            DOUBLE PRECISION,
+    ph_max            DOUBLE PRECISION,
     soil_texture_preference TEXT[],
     hardiness_zone_usda TEXT,
     hardiness_zone_at   TEXT,
-    min_temp          NUMERIC(5,2),
-    max_temp          NUMERIC(5,2),
+    min_temp          DOUBLE PRECISION,
+    max_temp          DOUBLE PRECISION,
     drought_tolerance drought_tolerance,
-    water_requirement_mm_week NUMERIC(5,2),
+    water_requirement_mm_week DOUBLE PRECISION,
     waterlogging_tolerance BOOLEAN,
     salt_tolerance    salt_tolerance,
     edibility_rating  SMALLINT,