…9055)

* Add integration test for `match: {except: []}` with integer index

Regression test for #9050

An empty `except` list (NOT IN []) should always match all points that
have the field, both with and without a payload index. Currently the
integer (and keyword) indexed path incorrectly returns zero results
because:

1. serde deserializes `except: []` as `AnyVariants::Strings([])` (first
   variant of the untagged enum)
2. The map index filter_impl returns `iter::empty()` for empty
   cross-type variant, instead of matching everything

The test covers:
- except: [] without any index (baseline, currently works)
- except: [] with an integer index (currently broken)
- except: [] with a keyword index (currently broken)

Co-authored-by: Cursor <[email protected]>

* Fix `match: {except: []}` returning zero results with payload index

Fixes #9050

Root cause: `except: []` deserializes as `AnyVariants::Strings([])`
due to the untagged serde enum trying `Strings` first. On an integer
index, the filter_impl matched `Except + Strings(empty)` and returned
`iter::empty()` (zero results). The same issue existed symmetrically
on keyword indexes with `Integers(empty)` and on UUID indexes with
`Integers(empty)`.

The fix: when the cross-type variant reaches the Except branch (e.g.
Strings on an integer index, Integers on a keyword/UUID index), return
`None` unconditionally — regardless of whether the set is empty. This
delegates to the fallback condition checker, which already handles
`except: []` correctly by matching all values.

The `estimate_cardinality_impl` functions had the same bug (returning
`CardinalityEstimation::exact(0)` for the empty cross-type case) and
are fixed the same way.

Affected index types: integer, keyword (str), UUID.
Bool index is NOT affected — it already returns `None` for all
Any/Except conditions.

Co-authored-by: Cursor <[email protected]>

* Expand match-except test to cover all index types and cross-type filters

Extends the regression test for #9050 to comprehensively cover:

- Integer, keyword, and UUID field indexes
- Empty except list (the original bug) for each index type
- Non-empty except list with matching types (normal filtering)
- Cross-type except values (e.g. strings on integer index, integers on
  keyword/UUID index) — type mismatch should exclude nothing → all match
- Exclude-all: listing every value should return zero results
- All scenarios tested both with and without a payload index

Co-authored-by: Cursor <[email protected]>

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Co-authored-by: Cursor Agent <[email protected]>
Co-authored-by: Cursor <[email protected]>