[eldraco]

Follow-up to #2209. This is the thirteenth, small-fix PR in the split series. It starts from the exact head of #2209 and leaves branches 1–12 unchanged.

Fixes

• Keep the terminal's evidence total consistent with retained evidence when records are removed or revised. This moves the post-split fix from parent commit 4f708bddb into this branch.
• Remember web investigation filters across tab changes, reloads, and new runs.
• Add the selected host's evidence grouping and source controls, and bring the Evidence tab's selected-group filters in line with those controls: inclusive severity, threat, module, and score-handling groups. Type counts cover all matching records; other group counts explicitly cover loaded records.
• Keep previous/next navigation in the order shown by the grouped record table.

Scope

This PR targets sebas/feat/web_investigation_redesign (#2209). The parent #2141 branch is restored to 8d6533186; no earlier split PR branch is changed. Unrelated local configuration, notes, datasets, and images are excluded.

Validation

• 74 alert-handler unit tests passed.
• 12 web API filter/grouping tests passed.
• 4 Chrome filter, paging, and persistence checks passed in light and dark themes.
• JavaScript syntax, diff whitespace checks, and commit hooks passed.