Mostly a clean removal of stale "experimental" warnings, plus a useful new update example for the insert/delete JSON format. Two real issues and a typo:

Blocker — docs.feldera.com/docs/sql/udf.md: the diff removes the opening :::warning Experimental feature admonition AND the opening :::danger fence, but leaves the matching closing ::: orphaned ~30 lines below (on its own line just before "Feldera supports UDFs implemented in Rust."). Docusaurus will then either swallow the next sibling block as the admonition body or render a literal :::. Please also drop that closing fence.

Same file, "SQL type representation in Rust" section: the :::caution Experimental feature admonition that survives this PR now has an empty body — the prose that justified the caution is exactly what's being removed elsewhere. Renders as an empty yellow box. Either delete it or replace its body with one sentence that actually says something.

Typo — docs.feldera.com/docs/formats/json.md line 215: "San Fransisco" → "San Francisco" in the new update example.

The other seven files (removing experimental warnings from NATS, checkpoint-sync, pipeline modification, transactions, ERROR_VIEW, the Jaeger tracing section, plus the "feture" → "feature" fix and a small word polish in grammar.md) all look fine.

Requesting changes for the orphan admonition fence; happy to re-approve once it's fixed.

All three blockers from my prior REQUEST_CHANGES (review 4520731866) are fixed in 4d3d6380:

• udf.md is no longer mangled — the orphan closing ::: is removed, and the :::danger block now wraps the entire Rust-UDF preamble cleanly (lines 18–45).
• The empty :::caution Experimental feature block in the SQL-type-representation section is gone.
• "San Fransisco" → "San Francisco" in the update example.

Net surviving doc deletions look right: NATS-input experimental warning, checkpoint-sync caution, modifying-pipeline warning, transactions warning, ERROR_VIEW warning, Rust-UDF experimental warning. WATERMARK grammar entries are commented out rather than deleted, which keeps them easy to restore when the feature lands.

LGTM.