Phase 3: declare component media that bubbles through the node tree

The JS-bearing widgets now declare their script dependencies, so a view
no longer needs to know which scripts a component requires:

- SearchSelect / FilterSelect → search_select.js
- RangeSlider → range_slider.js
- DateRangePicker → date_range_picker.js
- YearPicker → datepicker.umd.js (external, from Phase 2)
- FilterBar chrome → filter_bar.js

Because the filter-bar internals now build a node tree (the legacy
Component() string-builder calls became Element/Div), each bar's
collect_media() returns its own filter_bar.js merged with the scripts
that bubble up from the FilterSelect / RangeSlider / DateRangePicker
widgets it contains — exactly the set the views thread by hand today.

Adds Node.with_media() so a function-built node can declare media
without a full BaseComponent subclass, and tests proving the bubbling.

Note: the six *FilterBar functions still share the _filter_bar chrome
helper rather than a BaseComponent class hierarchy; folding them into
one is a follow-up that does not affect media collection (Phase 4).

https://claude.ai/code/session_01BKurBhE3Qj25p7Bfsg7EeK

common/components/search_select.py

@@ -23,9 +23,12 @@ from typing import TypedDict
 
 from django.utils.safestring import SafeText
 
-from common.components.core import Component, HTMLAttribute
+from common.components.core import Element, HTMLAttribute, Media, Node
 from common.components.primitives import Div, Input, Pill, Span, Template
 
+# Both comboboxes are wired by search_select.js.
+_SEARCH_SELECT_MEDIA = Media(js=("search_select.js",))
+
 
 class SearchSelectOption(TypedDict):
     value: str | int
@@ -322,12 +325,12 @@ def SearchSelect(
         always_visible=always_visible,
         items_visible=items_visible,
         templates=templates,
-    )
+    ).with_media(_SEARCH_SELECT_MEDIA)
 
 
-def _filter_remove_button() -> SafeText:
-    return Component(
-        tag_name="button",
+def _filter_remove_button() -> Node:
+    return Element(
+        "button",
         attributes=[
             ("type", "button"),
             ("data-pill-remove", ""),
@@ -369,9 +372,9 @@ def _filter_modifier_pill(modifier_value: str, label: str) -> SafeText:
     )
 
 
-def _filter_action_button(action: str, symbol: str, title: str) -> SafeText:
-    return Component(
-        tag_name="button",
+def _filter_action_button(action: str, symbol: str, title: str) -> Node:
+    return Element(
+        "button",
         attributes=[
             ("type", "button"),
             ("data-search-select-action", action),
@@ -557,7 +560,7 @@ def FilterSelect(
         always_visible=False,
         items_visible=items_visible,
         templates=templates,
-    )
+    ).with_media(_SEARCH_SELECT_MEDIA)
 
 
 def searchselect_selected(