fix(lib): stop the url sync from restoring a removed filter tag

[antontranelis]

Symptom

Filtering the map by hashtags worked, but the filters could not be removed again: clicking ✕ on a tag chip left the chip in place and the tag in the url.

Cause

removeFilterTag drops the tag from the filter state and rewrites the address bar in one go. The router location, however, still carries the old tags value for one render. A render log of the click makes it visible:

--- click ✕ ---
RENDER router.search="?tags=garten"  window.search=""             state=[]
RENDER router.search="?tags=garten"  window.search="?tags=garten"  state=[garten]

The sync effect ran on that stale location, saw a filter state that no longer matched the url, and restored the tag it had just removed — writing it back into the url as well. Because the effect listed filterTags among its dependencies, every state change triggered exactly this reconcile.

Fix

The sync now follows the url alone. It remembers the tags value it last applied and does nothing while that value is unchanged, so a state update can no longer trigger a reconcile against a stale location. It also waits for the available tags before recording anything, which keeps deep links such as /?tags=garten working when the tag list arrives late.

The effect moved out of UtopiaMapInner into useSyncFilterTagsWithUrl so it can be covered by tests.

Tests

Four cases in useSyncFilterTagsWithUrl.spec.tsx: reading one tag from the url, reading several, removing a tag, and removing one of two. The two removal tests fail without the fix.

The suite needs a real BrowserRouter. MemoryRouter cannot reproduce the regression because useFilter reads window.location, which MemoryRouter never touches — worth knowing before anyone rewrites these tests.

vitest run (52 passed), eslint --max-warnings 0 and tsc --noEmit all pass in lib.

Note

That useFilter reads the global window.location while the sync uses the router location is the underlying weakness that made this possible. This PR does not change it, to keep the fix small — it looks like a worthwhile follow-up.

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