feat(filters): pick listed filter parameters from selects

[revam]

Why

The filter editor only gave a condition a value picker when the server listed values for it, or when its parameter was a number. Everything else became a True/False condition:

• Conditions that take free text (an AniDB character or creator ID, a name) could not be given a value, and a saved one was read back as True/False, so saving the filter again dropped its parameter.
• Conditions with two parameters but no pairs (a character with an appearance, a creator with a role) were treated the same way, losing both parameters.
• A number parameter without a list opened an empty picker.

The server's filter expression help now sends one list per parameter: either PossibleParameters/PossibleSecondParameters or PossibleParameterPairs, never both, with ParameterName/SecondParameterName to label the inputs. This PR builds the editor on that, and supersedes the parameter editing of #1482.

Where this sits

• Branch: feat/filter-parameter-inputs, one commit on master. Independent of the other open PRs.
• Server: needs the server's filter expression help from the current core master (the name hints, the second-parameter lists, and pairs only for source genres and tags). Against an older core the inputs fall back to "Value"/"Second Value" labels, and the appearance and role are typed instead of picked.

What

One rule: a list from the server means you pick from it, never type; free text only when the server sends no list for that parameter.

• Every expression that takes a parameter gets a value widget (getWidgetKind): pairs or a second parameter make it a two-value condition, any parameter a one-value condition. Only parameterless expressions stay True/False. Saved conditions with free-text parameters now load and save with their values.
• MultiValueCriteriaModal picks in one of two ways:
  • One list when the server sends pairs, or a list for a single parameter: the existing click-to-add list, now labelled from the name hints (Source: Genre for pairs).
  • One input per parameter otherwise, each a select when that parameter is listed and a text input (a number input for Number) when it is not, with an Add button (and Enter). For example, "AniDB Character ID" is typed and "Appearance" is picked.
• Values are kept as their raw parameters and joined only for display, so a value containing : is never split wrongly. Duplicates and empty values cannot be added.
• FilterExpression gained ParameterName and SecondParameterName.

Look first at: src/components/Collection/Filter/MultiValueCriteriaModal.tsx (ParameterInput and the list or inputs branch), then getWidgetKind in src/core/utilities/filterTree.ts.

Feedback wanted

• A single listed parameter and pairs keep the click-to-add list rather than a <select>; only the per-parameter form uses selects. Is that split right, or should a single list become a select too?
• Character and creator IDs are typed by hand. A search-backed picker would suit them better; worth a follow-up?
• Labels fall back to "Value" and "Second Value" when the server sends no name. Fine, or should the expression's name be used instead?

Testing

• On the tip: pnpm lint, pnpm tscheck, pnpm test (199 passed; filterTree.test.ts gained cases for free-text parameters and two-parameter expressions without pairs) and pnpm build all pass. No dependency changes.
• Not yet tried against a running server.
• To try: in the filter editor, add "Has Character With Appearance": type a character ID, pick an appearance, Add, save, reopen and edit it again. Do the same with a source genre (one list of pairs) and a free-text condition such as a creator ID, and check that each keeps its values after saving and reloading.