docs: fix broken links by using .md extensions for cross-page refs

Author: lukekim

website/docs/faq/index.md

@@ -100,7 +100,7 @@ Spice uses [Apache DataFusion](https://datafusion.apache.org/) as its primary qu
 
 Yes. Spice supports streaming ingestion from several sources:
 
-- **Native PostgreSQL logical replication** (recommended for Postgres sources). Spice connects directly to the source using Postgres' `wal_level=logical` + pgoutput and streams `INSERT`/`UPDATE`/`DELETE` events into the accelerator — no Debezium, no Kafka, no external services. [Learn more](../features/cdc/postgres-replication).
+- **Native PostgreSQL logical replication** (recommended for Postgres sources). Spice connects directly to the source using Postgres' `wal_level=logical` + pgoutput and streams `INSERT`/`UPDATE`/`DELETE` events into the accelerator — no Debezium, no Kafka, no external services. [Learn more](../features/cdc/postgres-replication.md).
 - **[DynamoDB Streams](../components/data-connectors/dynamodb)** for Amazon DynamoDB sources — Spice consumes the table's change stream and applies `INSERT`/`UPDATE`/`DELETE` events to the accelerator with `refresh_mode: changes`.
 - **[Apache Kafka](../components/data-connectors/kafka)** for event-streaming topics — Spice consumes records directly with `refresh_mode: append` for real-time, append-only acceleration.
 - **[Debezium](../components/data-connectors/debezium)** (over Kafka), for sources where Debezium is already deployed, or for databases without a native Spice CDC path (MySQL, SQL Server, etc.). [Learn more](../features/cdc).

website/docs/features/cdc/index.md

@@ -35,7 +35,7 @@ Enabling CDC by setting `refresh_mode: changes` in the acceleration settings req
 
 Spice currently supports streaming ingestion via:
 
-- **[PostgreSQL Logical Replication](./postgres-replication)** — **recommended** for PostgreSQL sources. Spice connects directly to the source using Postgres' native logical replication protocol (`wal_level=logical` + pgoutput) and streams `INSERT`/`UPDATE`/`DELETE` events into the accelerator. No Kafka, no Debezium, no external services.
+- **[PostgreSQL Logical Replication](./postgres-replication.md)** — **recommended** for PostgreSQL sources. Spice connects directly to the source using Postgres' native logical replication protocol (`wal_level=logical` + pgoutput) and streams `INSERT`/`UPDATE`/`DELETE` events into the accelerator. No Kafka, no Debezium, no external services.
 - **[DynamoDB Streams](../../components/data-connectors/dynamodb#streams)** — for Amazon DynamoDB sources. Spice consumes the table's DynamoDB Streams directly and applies `INSERT`/`UPDATE`/`DELETE` events to the accelerator.
 - **[Apache Kafka](../../components/data-connectors/kafka)** — for event-streaming topics. Spice consumes records directly with `refresh_mode: append` for real-time, append-only acceleration (no separate CDC connector required).
 - **[Debezium](../../components/data-connectors/debezium)** (over Kafka) — for sources where Debezium + Kafka is already deployed, or for databases without a native Spice CDC path (MySQL, SQL Server, etc.).

website/docs/features/cdc/postgres-replication.md

@@ -289,6 +289,6 @@ For greenfield Postgres → Spice CDC, prefer native WAL streaming. If Kafka is
 
 ## See also
 
-- [Change Data Capture overview](./index)
+- [Change Data Capture overview](./index.md)
 - [PostgreSQL Data Connector](../../components/data-connectors/postgres)
 - [PostgreSQL: Logical Replication](https://www.postgresql.org/docs/current/logical-replication.html)