Remove redundant search bar from Home, rename page filters

- Remove SearchInput from Home page (use GlobalSearch in header instead)
- Rename "Search packages..." to "Filter packages..." on ProjectPage
- Rename "Search tags..." to "Filter tags..." on PackagePage
- Update FilterChip labels from "Search" to "Filter"

This differentiates the global search (header) from page-level filtering.

frontend/src/pages/ProjectPage.tsx

@@ -226,7 +226,7 @@ function ProjectPage() {
         <SearchInput
           value={search}
           onChange={handleSearchChange}
-          placeholder="Search packages..."
+          placeholder="Filter packages..."
           className="list-controls__search"
         />
         <select
@@ -246,7 +246,7 @@ function ProjectPage() {
 
       {hasActiveFilters && (
         <FilterChipGroup onClearAll={clearFilters}>
-          {search && <FilterChip label="Search" value={search} onRemove={() => handleSearchChange('')} />}
+          {search && <FilterChip label="Filter" value={search} onRemove={() => handleSearchChange('')} />}
           {format && <FilterChip label="Format" value={format} onRemove={() => handleFormatChange('')} />}
         </FilterChipGroup>
       )}