fix(docs): correct Array SQL function names, type OIDs, and WAL header layout

Rename all NDARRAY_* SQL functions to ARRAY_* to match the implemented
DDL surface (ARRAY_SLICE, ARRAY_PROJECT, ARRAY_AGG, ARRAY_ELEMENTWISE,
ARRAY_FLUSH, ARRAY_COMPACT, ALTER ARRAY, DROP ARRAY).

Correct pgwire type-OID table: split TIMESTAMP (1114, tz-naive) from
TIMESTAMPTZ (1184, UTC-normalised), add INTERVAL (1186) and VECTOR
(float4[], 1021), add usage guidance on which to prefer.

Update WAL segment header diagram to match current layout: record_type
widened to 4 bytes, tenant_id to 8 bytes, vshard_id to 4 bytes, 16-byte
reserved field added; total header 54 bytes. Document encryption flag
(bit 14 of record_type) and byte offsets.

Remove unimplemented SHOW/ALTER CONFLICT POLICY SQL from CRDT docs and
replace with accurate status note. Remove unimplemented CREATE SYNONYM
GROUP from FTS docs. Correct vector-search syntax from SEARCH...USING
VECTOR() to ORDER BY vector_distance(...) LIMIT k. Update SQL overview
vector-search operator list.

Author: farhan-syah

docs/reference/type-oids.rdx

@@ -7,17 +7,22 @@ description: PostgreSQL type OID mappings for pgwire protocol compatibility.
 
 NodeDB maps its types to PostgreSQL OIDs for pgwire compatibility.
 
-| NodeDB Type | PostgreSQL Type | OID  |
-| ----------- | --------------- | ---- |
-| STRING      | text            | 25   |
-| INT         | int8            | 20   |
-| FLOAT       | float8          | 701  |
-| BOOL        | bool            | 16   |
-| TIMESTAMP   | timestamptz     | 1184 |
-| UUID        | uuid            | 2950 |
-| DECIMAL     | numeric         | 1700 |
-| ARRAY       | jsonb           | 3802 |
-| OBJECT      | jsonb           | 3802 |
-| GEOMETRY    | bytea           | 17   |
+| NodeDB Type  | PostgreSQL Type | OID  |
+| ------------ | --------------- | ---- |
+| STRING       | text            | 25   |
+| INT          | int8            | 20   |
+| FLOAT        | float8          | 701  |
+| BOOL         | bool            | 16   |
+| TIMESTAMP    | timestamp       | 1114 |
+| TIMESTAMPTZ  | timestamptz     | 1184 |
+| INTERVAL     | interval        | 1186 |
+| UUID         | uuid            | 2950 |
+| DECIMAL      | numeric         | 1700 |
+| ARRAY        | jsonb           | 3802 |
+| OBJECT       | jsonb           | 3802 |
+| GEOMETRY     | bytea           | 17   |
+| VECTOR       | float4[]        | 1021 |
 
-Complex types (ARRAY, OBJECT) are serialized as JSONB over pgwire. GEOMETRY is serialized as WKB (bytea).
+`TIMESTAMP` (OID 1114) is timezone-naive. `TIMESTAMPTZ` (OID 1184) is UTC-normalised. Use `TIMESTAMPTZ` for wall-clock event times; `TIMESTAMP` for values that are inherently local (e.g. a schedule expressed in the user's timezone before conversion).
+
+Complex types (ARRAY, OBJECT) are serialized as JSONB over pgwire. GEOMETRY is serialized as WKB (bytea). VECTOR is serialized as a float4 array.

docs/reference/wal-segment-formats.rdx

@@ -8,12 +8,16 @@ description: On-disk format specifications for WAL records and segment files.
 ## WAL Record Format
 
 ```
-┌──────────┬─────────────────┬────────────┬─────┬───────────┬───────────┬─────────────┬─────────┐
-│  magic   │ format_version  │ record_type│ lsn │ tenant_id │ vshard_id │ payload_len │ crc32c  │
-│  4 bytes │    2 bytes      │   2 bytes  │ 8B  │   4 bytes │  2 bytes  │   4 bytes   │ 4 bytes │
-└──────────┴─────────────────┴────────────┴─────┴───────────┴───────────┴─────────────┴─────────┘
+┌─────────┬────────────────┬─────────────┬──────┬───────────┬───────────┬─────────────┬──────────┬─────────┐
+│  magic  │ format_version │ record_type │  lsn │ tenant_id │ vshard_id │ payload_len │ reserved │ crc32c  │
+│  4 bytes│    2 bytes     │   4 bytes   │  8B  │   8 bytes │  4 bytes  │   4 bytes   │ 16 bytes │ 4 bytes │
+└─────────┴────────────────┴─────────────┴──────┴───────────┴───────────┴─────────────┴──────────┴─────────┘
 ```
 
+Byte offsets: magic 0..4, format_version 4..6, record_type 6..10, lsn 10..18, tenant_id 18..26, vshard_id 26..30, payload_len 30..34, reserved 34..50, crc32c 50..54. Total header: **54 bytes**.
+
+Bit 14 of `record_type` signals AES-256-GCM encryption of the payload. The logical record type is `record_type & !(1 << 14)`.
+
 - Page size: 4 KiB or 16 KiB (O_DIRECT alignment)
 - CRC32C per page for bit-rot detection
 - Segmented with auto-rollover

docs/sql/crdt-operations.rdx

@@ -23,13 +23,4 @@ Applies a Loro CRDT delta to the document. On Origin, the delta goes through Raf
 
 ## Conflict Policies
 
-```sql
--- View current policy
-SHOW CONFLICT POLICY ON notes;
-
--- Set policy
-ALTER COLLECTION notes SET conflict_policy = 'lww';
-ALTER COLLECTION profiles SET conflict_policy = 'field_merge';
-```
-
-See [CRDT Sync](/docs/crdt-sync/overview) for full sync protocol details.
+Conflict policies (last-writer-wins, field-merge, custom) are configured per-collection at create time and via the native NodeDB protocol's `ALTER POLICY` command. SQL DDL for inspecting and updating conflict policies — `SHOW CONFLICT POLICY ON <collection>` and `ALTER COLLECTION ... SET ON CONFLICT ...` — is wired in the v0.1.0 release alongside the rest of the SQL surface. See the protocol reference for the native-protocol form, and [CRDT Sync](/docs/crdt-sync/overview) for full sync protocol details.

docs/sql/fulltext-search.rdx

@@ -20,13 +20,6 @@ ORDER BY score DESC LIMIT 20;
 SELECT title FROM articles WHERE text_match(title, 'databse', { fuzzy: true, distance: 2 });
 ```
 
-## Synonyms
-
-```sql
-CREATE SYNONYM GROUP db_terms AS ('database', 'db', 'datastore');
--- Searching for 'db performance' now also matches 'database performance'
-```
-
 ## CJK Search
 
 CJK text is automatically tokenized via character bigrams:

docs/sql/overview.rdx

@@ -34,7 +34,7 @@ NodeDB supports standard SQL with high PostgreSQL compatibility:
 
 Beyond standard SQL, NodeDB extends the language for each engine:
 
-- **Vector** — `SEARCH ... USING VECTOR()`, `vector_distance()`
+- **Vector** — `vector_distance()` with `<->` / `<=>` / `<#>` operators, ANN-aware `ORDER BY ... LIMIT k`
 - **Graph** — `GRAPH TRAVERSE`, `GRAPH ALGO`, `MATCH` patterns
 - **Full-Text** — `text_match()`, `bm25_score()`, `search_score()`
 - **Spatial** — `ST_DWithin()`, `ST_Contains()`, `ST_Distance()`, etc.

docs/sql/vector-search.rdx

@@ -8,18 +8,20 @@ description: Nearest neighbor search, filtered vector search, and multi-vector q
 ## Nearest Neighbor
 
 ```sql
-SEARCH articles USING VECTOR(embedding, ARRAY[0.1, 0.3, -0.2, ...], 10);
+SELECT id, vector_distance(embedding, ARRAY[0.1, 0.3, -0.2, ...]) AS dist
+FROM articles
+ORDER BY dist LIMIT 10;
 ```
 
-Returns the 10 nearest neighbors by the metric configured on the index (l2, cosine, inner_product, manhattan, chebyshev, hamming, jaccard, or pearson).
+Returns the 10 nearest neighbors by the metric configured on the index (l2, cosine, inner_product, manhattan, chebyshev, hamming, jaccard, or pearson). The planner detects `ORDER BY vector_distance(...) LIMIT k` and rewrites it into an ANN top-k plan; no special `SEARCH` keyword is required.
 
 ## Filtered Vector Search
 
 ```sql
 SELECT title, vector_distance(embedding, ARRAY[0.1, 0.3, ...]) AS score
 FROM articles
 WHERE category = 'machine-learning'
-  AND id IN (SEARCH articles USING VECTOR(embedding, ARRAY[0.1, 0.3, ...], 10));
+ORDER BY score LIMIT 10;
 ```
 
 The engine builds a Roaring Bitmap of matching IDs and selects the optimal strategy: pre-filter (selective filters), post-filter (broad filters), or brute-force (very selective).

docs/storage-engines/array.rdx

@@ -60,7 +60,7 @@ CREATE ARRAY spatial_grid
 | `cell_order`      | No       | `'Z-ORDER'` | `'Z-ORDER'` (Hilbert curve) or `'ROW-MAJOR'`. Affects spatial cache locality.                            |
 | `audit_retain_ms` | No       | `NULL`      | Tiles older than `now - audit_retain_ms` (system time) become eligible for purge. `NULL` = keep all.    |
 
-`ALTER NDARRAY <name> SET (audit_retain_ms = ...)` updates retention; `DROP ARRAY <name>` is two-phase like `DROP COLLECTION`.
+`ALTER ARRAY <name> SET (audit_retain_ms = ...)` updates retention; `DROP ARRAY <name>` is two-phase like `DROP COLLECTION`.
 
 ## Insert
 
@@ -79,17 +79,17 @@ INSERT INTO ARRAY elevation_map (lon, lat, height) VALUES
   (-73.7, 40.6, 8.9);
 
 -- Force the in-memory tiles to durable storage
-SELECT NDARRAY_FLUSH('elevation_map');
+SELECT ARRAY_FLUSH('elevation_map');
 ```
 
 ## Query Functions
 
 Array queries are expressed as table-valued functions in `FROM`. System time and valid time apply via `AS OF` clauses.
 
-### `NDARRAY_SLICE` — multi-dimensional range
+### `ARRAY_SLICE` — multi-dimensional range
 
 ```sql
-SELECT * FROM NDARRAY_SLICE(
+SELECT * FROM ARRAY_SLICE(
   'elevation_map',
   {lon: [-74.0, -73.0), lat: [40.0, 41.0)},
   ['height'],   -- attribute projection (optional)
@@ -104,37 +104,37 @@ SELECT * FROM NDARRAY_SLICE(
 | `attrs`   | No       | `ARRAY[STRING]`| Attributes to project. `NULL` = all attributes.                 |
 | `limit`   | No       | `INT64`        | Max cells returned. `NULL` = no limit.                          |
 
-### `NDARRAY_PROJECT` — attribute projection
+### `ARRAY_PROJECT` — attribute projection
 
 ```sql
-SELECT * FROM NDARRAY_PROJECT('spatial_grid', ['temperature', 'pressure']);
+SELECT * FROM ARRAY_PROJECT('spatial_grid', ['temperature', 'pressure']);
 ```
 
-### `NDARRAY_AGG` — reduce a dimension
+### `ARRAY_AGG` — reduce a dimension
 
 Aggregates an attribute over a dimension, reducing dimensionality:
 
 ```sql
 -- Sum temperature over x; result keeps y and z
-SELECT * FROM NDARRAY_AGG('spatial_grid', 'temperature', 'SUM', 'x');
+SELECT * FROM ARRAY_AGG('spatial_grid', 'temperature', 'SUM', 'x');
 ```
 
 Reducers: `'SUM'`, `'AVG'`, `'MIN'`, `'MAX'`, `'COUNT'`.
 
-### `NDARRAY_ELEMENTWISE` — between two arrays of the same shape
+### `ARRAY_ELEMENTWISE` — between two arrays of the same shape
 
 ```sql
-SELECT * FROM NDARRAY_ELEMENTWISE('current_grid', 'baseline_grid', 'SUBTRACT', 'temperature');
+SELECT * FROM ARRAY_ELEMENTWISE('current_grid', 'baseline_grid', 'SUBTRACT', 'temperature');
 ```
 
 ## Maintenance
 
 ```sql
-SELECT NDARRAY_FLUSH('spatial_grid');    -- force memtable flush
-SELECT NDARRAY_COMPACT('spatial_grid');  -- merge tile versions, reclaim space
+SELECT ARRAY_FLUSH('spatial_grid');    -- force memtable flush
+SELECT ARRAY_COMPACT('spatial_grid');  -- merge tile versions, reclaim space
 ```
 
-`NDARRAY_FLUSH` always returns `{result: true}` on success; failure raises. Compaction also runs automatically in the background.
+`ARRAY_FLUSH` always returns `{result: true}` on success; failure raises. Compaction also runs automatically in the background.
 
 ## Bitemporal Queries
 
@@ -145,15 +145,15 @@ Every array cell carries two times:
 
 ```sql
 -- Read cells as the array existed in the past
-SELECT * FROM NDARRAY_SLICE('data', {x: [0, 100), y: [0, 100)}, ['value'])
+SELECT * FROM ARRAY_SLICE('data', {x: [0, 100), y: [0, 100)}, ['value'])
 AS OF SYSTEM TIME 1700000000000;
 
 -- Read cells whose valid-time interval includes a given moment
-SELECT * FROM NDARRAY_SLICE('forecast', {x: [0, 100), y: [0, 100)}, ['temp'])
+SELECT * FROM ARRAY_SLICE('forecast', {x: [0, 100), y: [0, 100)}, ['temp'])
 AS OF VALID TIME 1700000000000;
 
 -- Both clauses combined
-SELECT * FROM NDARRAY_SLICE('forecast', {x: [0, 100), y: [0, 100)}, ['temp'])
+SELECT * FROM ARRAY_SLICE('forecast', {x: [0, 100), y: [0, 100)}, ['temp'])
 AS OF SYSTEM TIME 1700000000000 AS OF VALID TIME 1700000001000;
 ```
 
@@ -165,7 +165,7 @@ Array cells participate in surrogate-identity bitmaps with the rest of the engin
 
 ```sql
 SELECT *
-FROM NDARRAY_SLICE('spatial_data', {x: [0, 1000), y: [0, 1000)}, ['attr1', 'attr2'])
+FROM ARRAY_SLICE('spatial_data', {x: [0, 1000), y: [0, 1000)}, ['attr1', 'attr2'])
 WHERE id IN (
   SEARCH vectors USING VECTOR(embedding, $query, 100)
 );

docs/temporal/bitemporal.rdx

@@ -107,7 +107,7 @@ CREATE ARRAY climate_grid
   WITH (audit_retain_ms = 7776000000);  -- 90 days
 
 -- Cells as committed yesterday
-SELECT lon, lat, temp_c FROM NDARRAY_SLICE(
+SELECT lon, lat, temp_c FROM ARRAY_SLICE(
     'climate_grid',
     {lon: [-10, 10), lat: [0, 20)},
     ['temp_c']