docs: fix MDX/Mermaid build errors in v2 docs (#951)

Author: scarmuega

docs/v2/advanced/stateful_cursor.mdx

@@ -25,16 +25,19 @@ and resumes the source from there.
 Add a top-level `[cursor]` section to enable the feature, and pick a backend with `type`:
 
 <Tabs syncKey="cursor-backend">
-  <TabItem label="Memory">
+<TabItem label="Memory">
+
 Keeps the cursor in memory only — the position is **not** persisted across restarts. This is
 the default when no `[cursor]` section is present, and takes no extra fields.
 
 ```toml title="daemon.toml"
 [cursor]
 type = "Memory"
 ```
-  </TabItem>
-  <TabItem label="File">
+
+</TabItem>
+<TabItem label="File">
+
 Stores the cursor in a JSON file on the local file system.
 
 ```toml title="daemon.toml"
@@ -51,8 +54,10 @@ flush_interval = 10
   recover across rollbacks.
 - `flush_interval` (optional, default = `10`): how often, in seconds, the position is written
   to disk.
-  </TabItem>
-  <TabItem label="Redis">
+
+</TabItem>
+<TabItem label="Redis">
+
 Stores the cursor in a Redis instance — handy when running multiple environments or ephemeral
 containers.
 
@@ -70,5 +75,6 @@ flush_interval = 10
 - `max_breadcrumbs` (optional, default = `10`): how many recent positions to retain.
 - `flush_interval` (optional, default = `10`): how often, in seconds, the position is flushed
   to Redis.
-  </TabItem>
+
+</TabItem>
 </Tabs>

docs/v2/how_it_works.mdx

@@ -11,11 +11,11 @@ batches.
 
 ```mermaid
 flowchart LR
-    node([Cardano node]) -->|Ouroboros mini-protocols| source[Source]
+    cnode([Cardano node]) -->|Ouroboros mini-protocols| source[Source]
     source --> f1[Filter] --> f2[Filter] --> sink[Sink]
     sink --> dest([Destination])
-    sink -.reports position.-> cursor[(Cursor)]
-    cursor -.restores on restart.-> source
+    sink -. reports position .-> cursor[(Cursor)]
+    cursor -. restores on restart .-> source
 ```
 
 ## The pipeline