Python: restructure: Python samples into progressive 01-05 layout (#3862)

* restructure: Python samples into progressive 01-05 layout

- 01-get-started/: 6 numbered steps (hello agent → hosting)
- 02-agents/: all agent concept samples (tools, middleware, providers, etc.)
- 03-workflows/: ALL existing workflow samples preserved as-is
- 04-hosting/: azure-functions, durabletask, a2a
- 05-end-to-end/: demos, evaluation, hosted agents
- Old files moved to _to_delete/ for review
- Added AGENTS.md with structure documentation
- autogen-migration/ and semantic-kernel-migration/ preserved at root

* fix: switch to AzureOpenAI Foundry, fix CI failures

- Switch all 01-get-started samples to AzureOpenAIResponsesClient with
  Azure AI Foundry project endpoint (AZURE_AI_PROJECT_ENDPOINT +
  AZURE_OPENAI_RESPONSES_DEPLOYMENT_NAME + AzureCliCredential)
- Add _to_delete/ and 05-end-to-end/ to pyrightconfig.samples.json excludes
- Fix test paths in packages/ that referenced old getting_started/ dirs:
  durabletask conftest + streaming test, azurefunctions conftest,
  devui conftest + capture_messages + openai_sdk_integration
- Fix workflow_as_agent_human_in_the_loop.py import (sibling import)
- Update hosting READMEs and tool comment paths
- Replace root README.md with new structure overview
- Update AGENTS.md to document Azure OpenAI Foundry as default provider

* cleanup: remove _to_delete folder, copy resource files to active dirs

All files in _to_delete/ were either:
- Exact duplicates of files in the new structure (240 files)
- Same file with only comment path updates (100 files)
- One import-fix diff (workflow_as_agent_human_in_the_loop.py)
- One superseded minimal_sample.py

Resource files (sample.pdf, countries.json, employees.pdf, weather.json)
copied to 02-agents/sample_assets/ and 02-agents/resources/ since active
samples reference them.

* fix: address PR review comments, centralize resources, remove root duplicates

- Fix type annotation in 04_memory.py (string union -> proper types)
- Fix old sample paths in observability files
- Fix grammar/spelling in observability samples
- Move sample_assets/ and resources/ to shared/ folder
- Remove 8 duplicate observability files from 02-agents root
- Update resource path references in multimodal_input and provider samples

* fix: update broken links from old getting_started paths to new structure

- Update relative paths in READMEs: getting_started/ → 01-get-started/,
  02-agents/, 03-workflows/, 04-hosting/, 05-end-to-end/
- Fix absolute GitHub URLs in package READMEs
- Fix broken link in ollama package README

* fix: convert absolute GitHub URLs to relative paths for link checker

Absolute URLs to python/samples/ on main branch 404 until PR merges.
Converted to relative paths that linkspector can verify locally.

* fix: update link for handoff sample moved to orchestrations/

* fix: update chatkit-integration README path from demos/ to 05-end-to-end/

* fix: update broken links in orchestrations README to match flat directory structure

python/samples/03-workflows/declarative/conditional_workflow/README.md

@@ -0,0 +1,23 @@
+# Conditional Workflow Sample
+
+This sample demonstrates control flow with conditions:
+- If/else branching
+- Switch statements
+- Nested conditions
+
+## Files
+
+- `workflow.yaml` - The workflow definition
+- `main.py` - Python code to execute the workflow
+
+## Running
+
+```bash
+python main.py
+```
+
+## What It Does
+
+1. Takes a user's age as input
+2. Uses conditions to determine an age category
+3. Sends appropriate messages based on the category

python/samples/03-workflows/declarative/conditional_workflow/main.py

@@ -0,0 +1,52 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""
+Run the conditional workflow sample.
+
+Usage:
+    python main.py
+
+Demonstrates conditional branching based on age input.
+"""
+
+import asyncio
+from pathlib import Path
+
+from agent_framework.declarative import WorkflowFactory
+
+
+async def main() -> None:
+    """Run the conditional workflow with various age inputs."""
+    # Create a workflow factory
+    factory = WorkflowFactory()
+
+    # Load the workflow from YAML
+    workflow_path = Path(__file__).parent / "workflow.yaml"
+    workflow = factory.create_workflow_from_yaml_path(workflow_path)
+
+    print(f"Loaded workflow: {workflow.name}")
+    print("-" * 40)
+
+    # Print out the executors in this workflow
+    print("\nExecutors in workflow:")
+    for executor_id, executor in workflow.executors.items():
+        print(f"  - {executor_id}: {type(executor).__name__}")
+    print("-" * 40)
+
+    # Test with different ages
+    test_ages = [8, 15, 35, 70]
+
+    for age in test_ages:
+        print(f"\n--- Testing with age: {age} ---")
+
+        # Run the workflow with age input
+        result = await workflow.run({"age": age})
+        for output in result.get_outputs():
+            print(f"  Output: {output}")
+
+    print("\n" + "-" * 40)
+    print("Workflow completed for all test cases!")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

python/samples/03-workflows/declarative/conditional_workflow/workflow.yaml

@@ -0,0 +1,69 @@
+name: conditional-workflow
+description: Demonstrates conditional branching based on user input
+
+# Declare expected inputs with their types
+inputs:
+  age:
+    type: integer
+    description: The user's age in years
+
+actions:
+  # Get the age from input
+  - kind: SetValue
+    id: get_age
+    displayName: Get user age
+    path: Local.age
+    value: =inputs.age
+
+  # Determine age category using nested conditions
+  - kind: If
+    id: check_age
+    displayName: Check age category
+    condition: =Local.age < 13
+    then:
+      - kind: SetValue
+        path: Local.category
+        value: child
+      - kind: SendActivity
+        activity:
+          text: "Welcome, young one! Here are some fun activities for kids."
+    else:
+      - kind: If
+        condition: =Local.age < 20
+        then:
+          - kind: SetValue
+            path: Local.category
+            value: teenager
+          - kind: SendActivity
+            activity:
+              text: "Hey there! Check out these cool things for teens."
+        else:
+          - kind: If
+            condition: =Local.age < 65
+            then:
+              - kind: SetValue
+                path: Local.category
+                value: adult
+              - kind: SendActivity
+                activity:
+                  text: "Welcome! Here are our professional services."
+            else:
+              - kind: SetValue
+                path: Local.category
+                value: senior
+              - kind: SendActivity
+                activity:
+                  text: "Welcome! Enjoy our senior member benefits."
+
+  # Send a summary
+  - kind: SendActivity
+    id: summary
+    displayName: Send category summary
+    activity:
+      text: '=Concat("You have been categorized as: ", Local.category)'
+
+  # Store result
+  - kind: SetValue
+    id: set_output
+    path: Workflow.Outputs.category
+    value: =Local.category