docs: publish the Function pages only once Functions launch

The two Function pages declare `launch: functions`, and every other page
marks what it says about Functions, so the assembled site leaves them out
until the launch. Before it, the pages that offered Functions for Python
work point Enterprise readers at Geneva instead.

The SQL Function example now uses Arrow type names, which the server
requires, and states the 3.12 default for `python_version`.

docs/web/basics/catalog.mdx

@@ -3,7 +3,7 @@ title: "Lance Catalog"
 sidebarTitle: "Lance Catalog"
 description: "The naming layer: what objects exist, how they nest, and who may reach them."
 icon: sitemap
-keywords: ["catalog", "namespace", "hierarchy", "governance", "database", "table", "view", "function"]
+keywords: ["catalog", "namespace", "hierarchy", "governance", "database", "table", "view"]
 ---
 
 A catalog answers one question: **what exists, and what is it called.** It holds
@@ -25,12 +25,23 @@ resolves the same names to the same tables.
 | [Table](/management/table) | Rows and columns, versioned. What most operations act on. |
 | [Materialized view](/management/materialized-view) | A table whose contents come from a query, computed and stored. |
 | [View](/management/view) | A saved query. Computed when read, not stored. |
-| [Function](/management/function) | Registered code, applied to produce column values. |
+| [Function](/management/function) {/* if functions launched */} | Registered code, applied to produce column values. |
 
-Views and functions exist only on an Enterprise deployment that enables them.
+Views exist only on an Enterprise deployment that enables them.
+So do functions. {/* if functions launched */}
 Materialized views also exist in the embedded library, and a deployment has to
 enable them too.
 
+{/* if functions not launched */}
+```
+database
+└── namespace
+    ├── table
+    ├── materialized view      (a table, defined by a query)
+    └── view                   (a query, not stored)
+```
+{/* end if */}
+{/* if functions launched */}
 ```
 database
 └── namespace
@@ -39,6 +50,7 @@ database
     ├── view                   (a query, not stored)
     └── function
 ```
+{/* end if */}
 
 A namespace can contain further namespaces, so the hierarchy goes as deep as
 your organisation needs. A table is reached by its path through it:

docs/web/basics/jobs.mdx

@@ -14,8 +14,8 @@ availability:
 ---
 
 Some operations take longer than a request should. Building an index over a
-large table, refreshing a computed column, registering a function -- these run
-on the server after the call that started them has returned.
+large table or refreshing a computed column, for example, runs on the server
+after the call that started it has returned.
 
 Each is submitted the same way and returns the same handle.
 
@@ -36,7 +36,7 @@ a **job** immediately.
 | --- | --- | --- |
 | `create_index` | `create_index_async` | `CREATE INDEX` |
 | `refresh_column` | `refresh_column_async` | `REFRESH COLUMN` |
-| `create_function` | `create_function_async` | `CREATE FUNCTION` |
+| `create_function` {/* if functions launched */} | `create_function_async` | `CREATE FUNCTION` |
 | `drop_table` | `drop_table_async` | `DROP TABLE` |
 
 <Note>
@@ -76,8 +76,8 @@ returns the failed state rather than raising, which is what you want in a
 polling loop.
 
 In Python `wait` takes an optional timeout and returns the operation's typed
-result -- a `RefreshColumnJobResult`, a `FunctionVersion`, or `None` for an
-operation that has no result:
+result -- a `RefreshColumnJobResult`, for example, or `None` for an operation
+that has no result:
 
 ```python
 from datetime import timedelta

docs/web/basics/lakehouse.mdx

@@ -54,10 +54,10 @@ operation, not a separate service holding a second copy of your embeddings. See
 ### Compute {#compute}
 
 Deriving new columns and tables from what is already stored:
-[computed columns](/feature-engineering/add-computed-column),
-[functions](/management/function) that run Python where the data is, and
+[computed columns](/feature-engineering/add-computed-column) and
 [materialized views](/management/materialized-view) that persist a query's
 result.
+[Functions](/management/function) run Python where the data is. {/* if functions launched */}
 
 The reason this belongs in the lakehouse rather than in a pipeline outside it is
 the format. Adding a derived column writes only that column -- the images and

docs/web/basics/limits.mdx

@@ -97,7 +97,7 @@ not another.
 | SQL on a local database | unavailable; `execute_query` raises |
 | SQL on a deployment | needs its Flight SQL endpoint enabled and reachable |
 | SQL methods in the TypeScript SDK | none; use a Flight SQL client |
-| Function methods in the TypeScript SDK | none; use Python or SQL |
+| Function methods in the TypeScript SDK {/* if functions launched */} | none; use Python or SQL |
 | Vector search in SQL | [depends on the deployment](/basics/sql#no-vector-sql); the query builder always has it |
 | Geospatial `st_*` functions | behind a build feature LanceDB does not ship |
 | `tableExists` / `namespaceExists` in TypeScript | not present |

docs/web/basics/query.mdx

@@ -90,7 +90,7 @@ hybrid search has no SQL form. See [Semantic Search](/search).
 
 ## When the work outlives the call {#jobs}
 
-Some operations take longer than a query should: building an index, refreshing a
-computed column, registering a function. Those return a **job** rather than
+Some operations take longer than a query should: building an index, or
+refreshing a computed column. Those return a **job** rather than
 rows, and a job is a different handle with a different shape. See
 [Jobs](/basics/jobs).

docs/web/basics/sdk.mdx

@@ -42,9 +42,9 @@ Not every SDK covers the same surface, though:
 | Feature engineering, jobs | yes | partly |
 | Runs against a local database | yes | yes |
 
-Neither SDK aggregates or joins, and TypeScript has no methods for
-[functions](/management/function). Reach those with SQL on a deployment
-instead -- see [SQL](/basics/sql).
+Neither SDK aggregates or joins.
+TypeScript has no methods for [functions](/management/function). {/* if functions launched */}
+Reach those with SQL on a deployment instead -- see [SQL](/basics/sql).
 
 ## REST API {#rest}