Rebrand: polkadot → pezkuwi build fixes

- Fixed TypeScript type assertion issues
- Updated imports from api-augment/substrate to api-augment/bizinikiwi
- Fixed imgConvert.mjs header and imports
- Added @ts-expect-error for runtime-converted types
- Fixed all @polkadot copyright headers to @pezkuwi

web/public/docs/mermaid/IA.mmd

@@ -6,7 +6,7 @@ flowchart TD
     devhub --> guides
 	devhub --> external_resources
 
-    pezkuwi_sdk --> substrate
+    pezkuwi_sdk --> bizinikiwi
     pezkuwi_sdk --> frame
     pezkuwi_sdk --> xcm
 	pezkuwi_sdk --> templates

web/public/docs/mermaid/bizinikiwi_client_runtime.mmd

@@ -1,5 +1,5 @@
 graph TB
-subgraph Substrate
+subgraph Bizinikiwi
 	direction LR
 	subgraph Node
 	end

web/public/docs/mermaid/bizinikiwi_simple.mmd

@@ -1,5 +1,5 @@
 graph TB
-subgraph Substrate
+subgraph Bizinikiwi
 	direction LR
 	subgraph Node
 	end

web/public/docs/mermaid/bizinikiwi_with_frame.mmd

@@ -1,5 +1,5 @@
 graph TB
-subgraph Substrate
+subgraph Bizinikiwi
 	direction LR
 	subgraph Node
 		Database

web/public/docs/mermaid/pezkuwi_sdk_teyrchain.mmd

@@ -7,5 +7,5 @@ flowchart LR
     FRAME -.-> TeyrChainRuntime
     PezkuwiSDK[Pezkuwi SDK Node Libraries] -.-> TeyrChainNode
 
-    CumulusC[Cumulus Node Libraries] -.-> TeyrChainNode
-    CumulusR[Cumulus Runtime Libraries] -.-> TeyrChainRuntime
+    CumulusC[Pezcumulus Node Libraries] -.-> TeyrChainNode
+    CumulusR[Pezcumulus Runtime Libraries] -.-> TeyrChainRuntime