Search filters for size (MB) and file extensions

- API: min_size and max_size in MB, ext as a comma-separated list. An
  extension matches as a whole word in search_text (file and entry names,
  dots as spaces), so "iso" finds .iso files but not "ISOLATION", which a
  plain search word matched as a substring. The trigram index serves it.
- Web UI: a size range and an extension field in the filter row, kept in
  the URL like the other filters.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/app.js

@@ -3,6 +3,8 @@
 
 const $ = (selector) => document.querySelector(selector)
 const FILTERS = ['readable', 'complete', 'hide_encrypted', 'par2_only']
+/** Text inputs that narrow a search: size bounds in MB and file extensions. */
+const FIELDS = ['min_size', 'max_size', 'ext']
 const SOURCE_LABELS = {
   stem: 'Filename',
   subject: 'Subject',
@@ -19,6 +21,9 @@ const state = {
   sort: 'newest',
   source: '',
   poster: '',
+  min_size: '',
+  max_size: '',
+  ext: '',
   readable: false,
   complete: false,
   hide_encrypted: false,
@@ -90,6 +95,7 @@ function readUrl() {
   state.sort = params.get('sort') ?? 'newest'
   state.source = params.get('source') ?? ''
   state.poster = params.get('poster') ?? ''
+  for (const k of FIELDS) state[k] = params.get(k) ?? ''
   for (const f of FILTERS) state[f] = params.get(f) === '1'
   state.release = params.get('release') ? Number(params.get('release')) : null
 }
@@ -100,6 +106,7 @@ function writeUrl(push = false) {
   if (state.sort !== 'newest') params.set('sort', state.sort)
   if (state.source) params.set('source', state.source)
   if (state.poster) params.set('poster', state.poster)
+  for (const k of FIELDS) if (state[k]) params.set(k, state[k])
   for (const f of FILTERS) if (state[f]) params.set(f, '1')
   if (state.release) params.set('release', String(state.release))
   const url = `${location.pathname}${params.size ? `?${params}` : ''}`
@@ -110,6 +117,7 @@ function syncControls() {
   $('#q').value = state.q
   $('#sort').value = state.sort
   $('#source').value = state.source
+  for (const k of FIELDS) $(`#${k}`).value = state[k]
   for (const f of FILTERS) {
     document.querySelector(`[data-filter="${f}"]`).setAttribute('aria-pressed', String(state[f]))
   }
@@ -130,6 +138,7 @@ function searchParams(page) {
   if (state.q) params.set('q', state.q)
   if (state.source) params.set('source', state.source)
   if (state.poster) params.set('poster', state.poster)
+  for (const k of FIELDS) if (state[k]) params.set(k, state[k])
   for (const f of FILTERS) if (state[f]) params.set(f, '1')
   return params
 }
@@ -483,6 +492,12 @@ $('#q').addEventListener('input', (event) => {
   state.q = event.target.value.trim()
   scheduleSearch()
 })
+for (const k of FIELDS) {
+  $(`#${k}`).addEventListener('input', (event) => {
+    state[k] = event.target.value.trim()
+    scheduleSearch()
+  })
+}
 $('#sort').addEventListener('change', (event) => {
   state.sort = event.target.value
   writeUrl()
@@ -528,7 +543,7 @@ window.addEventListener('popstate', () => {
   const previous = { ...state }
   readUrl()
   syncControls()
-  const searchChanged = ['q', 'sort', 'source', 'poster', ...FILTERS].some((k) => previous[k] !== state[k])
+  const searchChanged = ['q', 'sort', 'source', 'poster', ...FIELDS, ...FILTERS].some((k) => previous[k] !== state[k])
   if (searchChanged) loadResults()
   if (state.release && state.release !== previous.release) openRelease(state.release)
   if (!state.release && previous.release) {