fix(packets): leaving with the SlideOver open rewrites the new page's URL; Clear Filters on a detail URL re-filters on reload

[dborup]

Summary

Two pre-existing URL/state bugs on the packets page. The independent review of PR #167 (fix for #147) found both. Neither is caused by #167. Line numbers refer to #167's head d0a9f28e; the same behaviour exists on master 84c637ea.

Relates to #147, #167.

1. Leaving the page with the SlideOver open overwrites the new page's URL

Where: viewport 641–1023 px, where the packet detail opens in a SlideOver.

Steps:

1. Open a packet so the SlideOver shows.
2. Navigate to another page (for example Nodes) without closing the SlideOver.

Result: the Nodes page renders, but the address bar is rewritten to the packets route:

• on master: #/packets;
• on fix(packets): keep ?obs=/?viewPath= on packet detail URLs (#147) #167: #/packets?timeWindow=…&region=…&sort=….

A reload or a copied link opens Packets, not the page being shown. The likely cause is the SlideOver close / onClose handler (public/packets.js ~3184), which writes the packets hash during teardown even after the route has changed.

Fix: when the SlideOver (or detail) closes because the page is being left, do not write the hash. Only write it while the current route is still #/packets. Compare the current route before writing, or tear the SlideOver down from destroy() without the hash write.

Test: an E2E at about 800 px: open the SlideOver, navigate to #/nodes, and assert that the address bar is #/nodes…. Repeat after a reload.

2. Clear Filters on a detail URL leaves the subpath, so a reload re-applies the hash filter

Steps:

1. Open #/packets/<hash>?… with filters, so the list shows 1 row.
2. Press Clear Filters. The list shows all rows (36 in the fixture), and the Clear button hides.
3. Reload.

Result: filters.hash is set from the <hash> subpath again, the list goes back to 1 row, and the Clear button reappears. The URL after Clear (#/packets/<hash>?obs=…) still means "filtered to this hash" on load, so it does not describe what Clear showed.

Fix (decide and document):

• Either Clear Filters also drops the detail subpath, closing the detail and going to #/packets;
• or a cold load of a detail subpath selects the packet without forcing filters.hash.

Keep #121/#132's Clear Filters behaviour intact otherwise.

Test: unit and/or E2E covering detail URL → Clear Filters → reload, asserting that the list and the Clear button match what was shown before the reload.

Acceptance criteria

• Both scenarios have a test that fails on master and passes with the fix.
• AGENTS.md deep-link rule: after each step, the URL describes what is shown.
• No change to buildPacketsQuery() output for non-hash callers.
• Do not start until fix(packets): keep ?obs=/?viewPath= on packet detail URLs (#147) #167 is merged (same file, public/packets.js).

[dborup]

Two updates from PR #167 round 2 (head 4b4163b3)

3. New pre-existing finding: the SlideOver's close button sits under the top nav at 641–1023 px

At about 800 px, the SlideOver's × close button is placed underneath .top-nav, so a real click lands on the nav and not on the button. PR #167's E2E closes the SlideOver by clicking the backdrop for that reason. It is not caused by #167.

• Fix: give the SlideOver a top offset or z-index that clears the top nav, using existing CSS variables. Touch targets should stay at 48×48 (style.css declares .nav-btn and .ch-icon-btn at both 48px and 44px Kpa-clawbot/CoreScope#2052 house rule).
• Test: an E2E at 800 px that closes the SlideOver with a real click on ×, plus a check that the button is the topmost element at its centre (document.elementFromPoint).

Item 1 may already be fixed by #167

#167 round 2 adds a route guard: updatePacketsUrl() only writes the packets URL while the route is #/packets. In one browser run at 800 px, clicking Nodes with the SlideOver open went to #/nodes and the URL was not rewritten. This was observed once and has no test, and the original bug was not reproduced on #167's earlier head either.

After #167 is merged, re-check item 1 before working on it. If it is fixed, add the regression test described above and close that item.

[dborup]

Update after #167 merged (bedbe1f1)

Item 1 is fixed by #167. The route guard means updatePacketsUrl() only writes the packets URL while the route is #/packets. Minimax's re-review reproduced the bug at 800 px with the SlideOver open: on #167's earlier head d0a9f28e, the page showed Nodes while the address bar said #/packets. On the merged head it shows #/nodes. The only test is a unit test of the guard; an E2E for this scenario is still missing.

Items 2 (Clear Filters on a detail URL) and 3 (SlideOver × under the top nav at 641–1023 px) are still open.

New findings from the #167 round-2 re-review

4. Escape is swallowed by the View Path modal even when another layer is on top. public/packet-path-map.js ~83 installs a capture-phase Escape handler that stops propagation.

   • Repro: open View Path, then press Ctrl+K. The global search (z-index 300) sits above the modal (z-index 200) with focus in its input.
   • Result: the first Escape closes the modal underneath, and the search stays open.
   • Also affected (by analysis only): the nav menu (app.js ~1938), the More sheet (bottom-nav.js ~404) and filter-ux.
   • Fix idea: do not stop the event when focus is outside the modal, or check which layer is topmost.

5. Back/forward can reopen a closed View Path modal.

   • The modal does not close on route change (pre-existing), and since fix(packets): keep ?obs=/?viewPath= on packet detail URLs (#147) #167 the View Path button writes viewPath=1 (user decision).
   • Repro: open the modal via the button, press Back (the modal stays over #/nodes), close it with Escape, then press Forward. It reopens because the packets history entry still carries viewPath=1.
   • Fix idea: close the modal on route change, and drop viewPath from the entry when the modal is closed while another route is shown.

6. Escape never closes the mobile detail sheet at ≤640 px (pre-existing, same on master). closeDetailPanel() (public/packets.js ~937) only handles #pktRight.

Each item needs a test that fails before the fix, and E2E at the relevant viewport.

[dborup]

Fixed by #204 (merged as c91a793f): points 2–6 of this issue are resolved. Point 1 was already fixed by #167.

• Clear Filters drops the detail subpath.
• The SlideOver × at 641–1023 px is clickable and 48 px.
• View Path no longer swallows Escape when a layer is on top of it.
• Back/forward no longer reopens a closed View Path.
• Escape closes the ≤640 px sheet.

The review follow-up (a test gap for Escape inside the modal) is tracked in #208.