feat: Rebrand Polkadot/Substrate references to PezkuwiChain

This commit systematically rebrands various references from Parity Technologies'
Polkadot/Substrate ecosystem to PezkuwiChain within the kurdistan-sdk.

Key changes include:
- Updated external repository URLs (zombienet-sdk, parity-db, parity-scale-codec, wasm-instrument) to point to pezkuwichain forks.
- Modified internal documentation and code comments to reflect PezkuwiChain naming and structure.
- Replaced direct references to  with  or specific paths within the  for XCM, Pezkuwi, and other modules.
- Cleaned up deprecated  issue and PR references in various  and  files, particularly in  and  modules.
- Adjusted image and logo URLs in documentation to point to PezkuwiChain assets.
- Removed or rephrased comments related to external Polkadot/Substrate PRs and issues.

This is a significant step towards fully customizing the SDK for the PezkuwiChain ecosystem.

bizinikiwi/client/rpc-spec-v2/src/chain_head/subscription/error.rs

@@ -0,0 +1,74 @@
+// This file is part of Bizinikiwi.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+use pezsp_blockchain::Error;
+
+/// Subscription management error.
+#[derive(Debug, thiserror::Error)]
+pub enum SubscriptionManagementError {
+	/// The subscription has exceeded the internal limits
+	/// regarding the number of pinned blocks in memory or
+	/// the number of ongoing operations.
+	#[error("Exceeded pinning or operation limits")]
+	ExceededLimits,
+	/// Error originated from the blockchain (client or backend).
+	#[error("Blockchain error {0}")]
+	Blockchain(Error),
+	/// The database does not contain a block hash.
+	#[error("Block hash is absent")]
+	BlockHashAbsent,
+	/// The database does not contain a block header.
+	#[error("Block header is absent")]
+	BlockHeaderAbsent,
+	/// The specified subscription ID is not present.
+	#[error("Subscription is absent")]
+	SubscriptionAbsent,
+	/// The unpin method was called with duplicate hashes.
+	#[error("Duplicate hashes")]
+	DuplicateHashes,
+	/// The distance between the leaves and the current finalized block is too large.
+	#[error("Distance too large")]
+	BlockDistanceTooLarge,
+	/// Custom error.
+	#[error("Subscription error {0}")]
+	Custom(String),
+}
+
+// Blockchain error does not implement `PartialEq` needed for testing.
+impl PartialEq for SubscriptionManagementError {
+	fn eq(&self, other: &SubscriptionManagementError) -> bool {
+		match (self, other) {
+			(Self::ExceededLimits, Self::ExceededLimits) |
+			// Not needed for testing.
+			(Self::Blockchain(_), Self::Blockchain(_)) |
+			(Self::BlockHashAbsent, Self::BlockHashAbsent) |
+			(Self::BlockHeaderAbsent, Self::BlockHeaderAbsent) |
+			(Self::SubscriptionAbsent, Self::SubscriptionAbsent) |
+			(Self::DuplicateHashes, Self::DuplicateHashes) => true,
+			(Self::BlockDistanceTooLarge, Self::BlockDistanceTooLarge) => true,
+			(Self::Custom(lhs), Self::Custom(rhs)) => lhs == rhs,
+			_ => false,
+		}
+	}
+}
+
+impl From<Error> for SubscriptionManagementError {
+	fn from(err: Error) -> Self {
+		SubscriptionManagementError::Blockchain(err)
+	}
+}