Add snippet-library search, sort, empty states, storage monitor (M6, §02/§09D)

docs/spec/02-snippet-library.md

@@ -10,7 +10,7 @@ The list shows every saved snippet and is always visible. A persistent "Create N
 - A "Create New Snippet" item is pinned at the top of the list; activating it creates and selects a new snippet (see _Snippet Operations_).
 - Selecting a snippet makes it the **active snippet**: it loads into the editor and preview, becomes highlighted in the list, and the URL updates to reflect the selected snippet so the state is shareable and survives a page reload (see _Application Shell & Navigation_).
 - Exactly one snippet is active at a time.
-- When no snippets match the current search, the list shows an empty-state message ("No snippets match your search"); when there are genuinely no snippets, it shows "No snippets found".
+- When no snippets match the current search, the list shows an empty-state message ("No snippets match your search", with a hint to try a different term); when there are genuinely no snippets, it shows "No snippets yet" with a nudge to create one.
 - On first run, when no snippets exist, the app seeds one sample bar-chart snippet so the user starts with a working example.
 
 ## List Item
@@ -78,5 +78,5 @@ A small indicator at the bottom of the library shows how much of the snippet sto
 
 - Displays current usage against the total budget (used vs. total), where the practical snippet budget is about 5 MB.
 - A fill indicator reflects the percentage used.
-- The indicator enters escalating warning states as usage climbs (a cautionary state past roughly 70% and a critical state past roughly 90%).
+- The indicator enters escalating warning states as usage climbs (a cautionary state past roughly 80% and a critical state past roughly 95%).
 - When storage is full, a save may fail; the system warns the user that the snippet could not be saved rather than silently losing data, so the user can delete snippets to free space.