Adds the 'Oracle-to-PostgreSQL Migration Expert' Custom Agent, Asociated Skills, and Plugin Manifest (#950)

* Add the 'Oracle-to-PostgreSQL Migration Expert' Custom Agent, its associated skills, plugin manifest

* Update READMEs using 'npm run build'

* Resolve PR comments:
- Fix BOM characters
- Rerun 'npm run build'
- Clarify timestampz date kind
- Remove consufing text for SELECT INTO exception
- Remove dangerous VB.NET example

* Update README and refcursor handling documentation for clarity and consistency

* Update skills/creating-oracle-to-postgres-master-migration-plan/SKILL.md

Add .slnx to discovery of projects

Co-authored-by: Aaron Powell <me@aaron-powell.com>

---------

Co-authored-by: TCPrimedPaul <paul.delannoy@tc.gc.ca>
Co-authored-by: Aaron Powell <me@aaron-powell.com>

plugins/oracle-to-postgres-migration-expert/.github/plugin/plugin.json

@@ -0,0 +1,32 @@
+{
+  "name": "oracle-to-postgres-migration-expert",
+  "description": "Expert agent for Oracle-to-PostgreSQL application migrations in .NET solutions. Performs code edits, runs commands, and invokes extension tools to migrate .NET/Oracle data access patterns to PostgreSQL.",
+  "version": "1.0.0",
+  "author": {
+    "name": "Awesome Copilot Community"
+  },
+  "repository": "https://github.com/github/awesome-copilot",
+  "license": "MIT",
+  "keywords": [
+    "oracle",
+    "postgresql",
+    "database-migration",
+    "dotnet",
+    "sql",
+    "migration",
+    "integration-testing",
+    "stored-procedures"
+  ],
+  "agents": [
+    "./agents/oracle-to-postgres-migration-expert.md"
+  ],
+  "skills": [
+    "./skills/creating-oracle-to-postgres-master-migration-plan/",
+    "./skills/creating-oracle-to-postgres-migration-bug-report/",
+    "./skills/creating-oracle-to-postgres-migration-integration-tests/",
+    "./skills/migrating-oracle-to-postgres-stored-procedures/",
+    "./skills/planning-oracle-to-postgres-migration-integration-testing/",
+    "./skills/reviewing-oracle-to-postgres-migration/",
+    "./skills/scaffolding-oracle-to-postgres-migration-test-project/"
+  ]
+}