feat: Add rebrand CI/CD workflows to main branch

- Add 72 rebrand workflow files (polkadot→pezkuwi, substrate→bizinikiwi, cumulus→pezcumulus)
- Add GitHub actions, issue templates, and configs
- Removed unnecessary workflows (fork-sync, gitspiegel, upstream-tracker, sync-templates, backport)
- Renamed zombienet test files to match new naming convention

.github/codecov.yml

@@ -0,0 +1,15 @@
+coverage:
+  precision: 2
+  round: down
+  range: "1...100"
+  status:
+    project:
+      default:
+        target: 1.0
+        threshold: 2.0
+
+comment:
+  behavior: new
+
+fixes:
+  - "/__w/pezkuwi-sdk/pezkuwi-sdk/::"