fix(search): dropdown dead on htmx-less pages; Alpine-side debounce; auto bundle stamps

The "top search bar doesn't work" report had TWO stacked causes, found
by reproducing with real keypress-by-keypress typing instead of
Playwright's fill() (which fires a single input event and masked both):

1. htmx.min.js was included PER PAGE. The header's live search is
   htmx-driven on every page, but five pages rendering @Header —
   series, admin, admin hash-conflicts, admin processing-issues,
   browse-detail — never loaded it: the input's hx-* attributes were
   inert (htmx-internal-data absent), so typing produced no request at
   all. The include now lives in the header partial itself (classic
   script, before the module bundle); the sixteen per-page copies on
   @Header pages are removed (double-processing guard). Non-header
   pages (login/register/setup/reader/index) keep their own.

2. htmx's delay: modifier on a PROGRAMMATICALLY dispatched custom event
   (htmx.trigger) loses the request entirely under rapid successive
   triggers — every re-fire canceled the pending timer and the last
   never issued, so fast typing (the normal kind) never opened the
   dropdown while one-shot fill() worked. The debounce moved into the
   Alpine component (client-local state, where it belongs); htmx now
   executes the bare `search` event immediately.

Also made bundle staleness structurally impossible: each bundle's
script stamp is a content hash computed at startup (templates/
bundles.go), so a rebuild that changes bundle bytes changes its cache
key with no manual ?v=N bump — the manual stamp was how the first
dropdown fix stayed invisible for a deploy. The reader bundle (never
stamped at all) is covered too. HTML pages additionally send
Cache-Control: no-cache (they are dynamic), so a stale page can no
longer reference a stale stamp; /api, /static and /uploads keep their
native caching, pinned by a middleware test.

templates/collection_rules_templ.go

@@ -42,7 +42,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
-		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 2, " - Bookhoard</title><script src=\"/static/htmx.min.js\"></script><link href=\"/static/style.css\" rel=\"stylesheet\"><link rel=\"icon\" type=\"image/svg+xml\" href=\"/static/favicon.svg\"></head>")
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 2, " - Bookhoard</title><link href=\"/static/style.css\" rel=\"stylesheet\"><link rel=\"icon\" type=\"image/svg+xml\" href=\"/static/favicon.svg\"></head>")
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
@@ -71,7 +71,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		var templ_7745c5c3_Var5 string
 		templ_7745c5c3_Var5, templ_7745c5c3_Err = templ.ResolveAttributeValue("initCollectionRules('" + collection.ID + "')")
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 14, Col: 120}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 13, Col: 120}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ_7745c5c3_Var5)
 		if templ_7745c5c3_Err != nil {
@@ -100,7 +100,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		var templ_7745c5c3_Var6 string
 		templ_7745c5c3_Var6, templ_7745c5c3_Err = templruntime.SanitizeStyleAttributeValues("background-color: var(--accent-muted); color: " + collection.Color)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 23, Col: 159}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 22, Col: 159}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var6))
 		if templ_7745c5c3_Err != nil {
@@ -113,7 +113,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		var templ_7745c5c3_Var7 string
 		templ_7745c5c3_Var7, templ_7745c5c3_Err = templ.JoinStringErrs(collection.Icon)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 23, Col: 179}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 22, Col: 179}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var7))
 		if templ_7745c5c3_Err != nil {
@@ -126,7 +126,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		var templ_7745c5c3_Var8 string
 		templ_7745c5c3_Var8, templ_7745c5c3_Err = templ.JoinStringErrs(collection.Name)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 25, Col: 90}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 24, Col: 90}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var8))
 		if templ_7745c5c3_Err != nil {
@@ -147,7 +147,7 @@ func CollectionRules(user User, collection CollectionData) templ.Component {
 		var templ_7745c5c3_Var9 string
 		templ_7745c5c3_Var9, templ_7745c5c3_Err = templ.ResolveAttributeValue(collection.ID)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 49, Col: 67}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/collection_rules.templ`, Line: 48, Col: 67}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ_7745c5c3_Var9)
 		if templ_7745c5c3_Err != nil {