…#9969)

# Which issue does this PR close?

- Follow-up to #9877; completes the remaining scope of #9667 (making
`BloomFilterProperties` fields non-public and exposing accessors).

# Rationale for this change

#9877 introduced `BloomFilterPropertiesBuilder`. With the builder in
place, the public `fpp` / `ndv` fields constrain future evolution.
Locking them down behind accessors makes the public API smaller and more
evolvable, matching the original direction outlined in #9667.

# What changes are included in this PR?

- Make `BloomFilterProperties::fpp` and `BloomFilterProperties::ndv`
private fields
- Add `pub fn fpp(&self) -> f64` and `pub fn ndv(&self) -> u64` accessor
methods
- Move the per-field documentation verbatim onto the accessor methods so
it remains rendered by rustdoc (private fields are not rendered)

# Are these changes tested?
Yes — the existing test suite covers the affected paths

# Are there any user-facing changes?
**Yes — this is a breaking change to the public API.**

- External struct-literal construction no longer compiles:
```rust
// Before — no longer works
BloomFilterProperties { fpp: 0.01, ndv: 10_000 }

// Use the builder added in #9877 instead:
BloomFilterProperties::builder()
  .with_fpp(0.01)
  .with_max_ndv(10_000)
  .build()
```
- Direct field reads (props.fpp, props.ndv) no longer compile; use
props.fpp() / props.ndv() instead.

# Which issue does this PR close?
- Closes apache#9667.

# Rationale for this change
No builder exists for `BloomFilterProperties`, so callers write
`BloomFilterProperties { fpp, ndv }` literals — pinning field layout to
the API and skipping fpp validation. `WriterPropertiesBuilder` also has
no setter that takes a built `BloomFilterProperties`.

# What changes are included in this PR?
- `BloomFilterPropertiesBuilder` (`with_fpp`, `with_max_ndv`, `build`,
`try_build`). Two entry points per discussion in the issue:
`BloomFilterProperties::builder()` and
`BloomFilterPropertiesBuilder::new()`.
- `WriterPropertiesBuilder::set_bloom_filter_properties` + per-column
variant. NDV from the passed-in struct is honoured (no row-group-size
override). For dynamic NDV, keep using `set_bloom_filter_enabled` /
`set_bloom_filter_fpp`.
- Renamed `set_bloom_filter_ndv` → `set_bloom_filter_max_ndv` (also
per-column). Old names are `#[deprecated(since = "59.0.0")]` aliases.


# Are these changes tested?
Yes — 10 new unit tests + a doc-test.

# Are there any user-facing changes?
Additive only. `set_bloom_filter_ndv` (and per-column) emit a
deprecation warning pointing to `_max_ndv`.

…apache#9969)

# Which issue does this PR close?

- Follow-up to apache#9877; completes the remaining scope of apache#9667 (making
`BloomFilterProperties` fields non-public and exposing accessors).

# Rationale for this change

apache#9877 introduced `BloomFilterPropertiesBuilder`. With the builder in
place, the public `fpp` / `ndv` fields constrain future evolution.
Locking them down behind accessors makes the public API smaller and more
evolvable, matching the original direction outlined in apache#9667.

# What changes are included in this PR?

- Make `BloomFilterProperties::fpp` and `BloomFilterProperties::ndv`
private fields
- Add `pub fn fpp(&self) -> f64` and `pub fn ndv(&self) -> u64` accessor
methods
- Move the per-field documentation verbatim onto the accessor methods so
it remains rendered by rustdoc (private fields are not rendered)

# Are these changes tested?
Yes — the existing test suite covers the affected paths

# Are there any user-facing changes?
**Yes — this is a breaking change to the public API.**

- External struct-literal construction no longer compiles:
```rust
// Before — no longer works
BloomFilterProperties { fpp: 0.01, ndv: 10_000 }

// Use the builder added in apache#9877 instead:
BloomFilterProperties::builder()
  .with_fpp(0.01)
  .with_max_ndv(10_000)
  .build()
```
- Direct field reads (props.fpp, props.ndv) no longer compile; use
props.fpp() / props.ndv() instead.