docs: complete SQL reference, enrich Functions drafts, rename OSS to Embedded (#4732)

## Summary

- Complete the SQL reference: `ATTACH DATABASE`, the `CHANGES` clause,
and
`dedupe()`/`duplicate_pairs()` (verified against current sophon source;
these were recently renamed from
`vector_dedup`/`vector_duplicate_pairs`).
  Fix the blob-column default-projection claim and add the previously
  undocumented `blob_descriptor()`.
- Enrich the gated Functions draft (still `.mintignore`'d, pre-release):
  chained Functions over blob outputs, GPU-produced blobs, Secrets,
  multi-input/output binding, `code=[module]` packaging.
- Upgrade the materialized-view and computed-column auto-refresh drafts
with
  precise, verified catch-up semantics, and add the missing `ALTER
  MATERIALIZED VIEW` / `CREATE ... WITH(...)` sections (also gated — the
  automatic-refresh scheduler is still dev/staging-only).
- Thread one running example (video frames → GPU extract/caption → dedup
→
auto-refreshing materialized view) through Functions, materialized
views,
and the LeRobotDataset integration guide instead of a separate tutorial.
- Rename "LanceDB OSS"/"OSS" to "LanceDB Embedded"/"Embedded" throughout
  (52 files); activate the existing availability-comparison mechanism on
  `basics/offerings.mdx` for a full feature-by-feature comparison table.

docs/web/sql/ddl/function.mdx

@@ -17,6 +17,15 @@ AS 'def f(x): return x * 2'
 WITH (pip = 'numpy==1.26.4', python_version = '3.11')
 ```
 
+A function takes more than one parameter; each one binds a separate column
+or literal where the function is called:
+
+```sql
+CREATE FUNCTION ratio(numerator float64, denominator float64) RETURNS float64
+LANGUAGE python
+AS 'def ratio(numerator, denominator): return numerator / denominator'
+```
+
 Parameter and result types are Arrow type names, not SQL ones: `int64`,
 `float64`, `utf8`, `bool`, `date32`, and lists such as `list<float32>` or
 `fixed_size_list<float32, 768>`. `BIGINT` is refused. A parameter accepts nulls
@@ -51,6 +60,20 @@ version is unaffected.
 the function is baked into an image before the version becomes usable.
 </Note>
 
+## Call it {#call}
+
+Once registered, a function is callable by name in any query, the same as a
+built-in scalar function:
+
+```sql
+SELECT id, f(x) AS doubled FROM my_table
+```
+
+This is also the fastest way to check a new registration before binding it to
+a column: call it over a few rows, or over literal arguments, before
+committing to [a computed column](/sql/ddl/table#computed-column) that fills
+from it.
+
 ## SHOW FUNCTIONS {#show}
 
 ```sql