Python: Add regression tests for Entry JoinExecutor Workflow.Inputs initialization

[moonbox3]

Motivation and Context

Note: the original bug is already fixed in main. This PR is adding more tests around it.

When workflow.run() is called with a dict or string input, the Entry node (JoinExecutor with kind: 'Entry') must call _ensure_state_initialized to populate Workflow.Inputs. Without this, expressions like =inputs.age resolve to blank, causing conditions like =Local.age < 13 to always evaluate as true (blank is treated as 0), silently routing all inputs to the wrong branch.

Fixes #3948

Description

The root cause is that the Entry JoinExecutor was not initializing Workflow.Inputs before the workflow's action nodes began executing, leaving input-referencing expressions with no data to resolve. This PR adds two regression tests that directly exercise the broken path: one passing a dict input and asserting the correct conditional branch is taken for both child and adult ages, and one passing a string input and asserting it is accessible via inputs.input. These tests lock in the correct behavior and will catch any future regression in Entry node state initialization.

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the Contribution Guidelines
• All unit tests pass, and I have added new tests where possible
• Is this a breaking change? If yes, add "[BREAKING]" prefix to the title of the PR.

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Note: PR autogenerated by moonbox3's agent

[moonbox3]

Automated Code Review

Reviewers: 3 | Confidence: 98%

✓ Correctness

This diff only reformats three assert statements by inlining their f-string failure messages, removing the parenthesized multi-line form. The change is purely cosmetic and functionally equivalent — Python's assert statement accepts the message expression directly. No logic, correctness, or behavior is altered.

✓ Security Reliability

This diff only reformats assert statement message arguments from parenthesized multi-line strings to inline f-strings. There are no security or reliability concerns introduced — the changes are purely cosmetic and do not affect logic, resource handling, or trust boundaries.

✓ Test Coverage

The diff is a pure formatting change — it consolidates multi-line assert failure messages onto single lines. No logic, behaviour, or test coverage is added, removed, or altered. The assertions themselves remain semantically identical, and no new code paths are introduced. From a test-coverage perspective there is nothing to flag.

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Automated review by moonbox3's agents

[markwallace-microsoft]

Python Test Coverage Report •

File	Stmts	Miss	Cover	Missing
packages/azurefunctions/agent_framework_azurefunctions
_app.py	500	172	65%	261–262, 265, 267–269, 275, 277–280, 282–283, 285–287, 291, 294, 296, 298–299, 302–304, 306, 308, 316, 324–327, 330, 333, 338–339, 342–345, 348, 351–353, 364–367, 373, 375, 383–384, 387, 392–393, 395–396, 398, 401, 404, 406, 408, 410–412, 416–419, 421, 423–424, 426, 437–439, 443–444, 446–447, 449, 460–465, 473, 475, 481–483, 489–490, 492–493, 495–498, 502, 508, 527, 626–627, 735, 743–744, 764–766, 772–774, 780–782, 815–816, 876–877, 926–927, 932, 1014, 1017, 1026–1028, 1030–1032, 1034, 1036, 1047, 1049–1052, 1054, 1056–1057, 1059, 1066–1067, 1069–1070, 1072–1073, 1075, 1079, 1089–1091, 1093–1094, 1096–1098, 1105, 1107–1108, 1110, 1131, 1136, 1148, 1220, 1310, 1325–1328, 1353
packages/core/agent_framework
_types.py	1024	86	91%	59, 68–69, 123, 128, 147, 149, 153, 157, 159, 161, 163, 181, 185, 211, 233, 238, 243, 247, 273, 277, 632–633, 1004, 1066, 1083, 1101, 1106, 1124, 1134, 1151–1152, 1154, 1172–1173, 1175, 1182–1183, 1185, 1220, 1231–1232, 1234, 1272, 1499, 1551, 1642–1647, 1669, 1674, 1840, 1852, 2104, 2125, 2220, 2449, 2656, 2726, 2738, 2756, 2954–2956, 2959–2961, 2965, 2970, 2974, 3058–3060, 3089, 3143, 3162–3163, 3166–3170, 3176
packages/core/agent_framework/_workflows
_workflow.py	260	19	92%	87, 268–270, 272–273, 291, 295, 423, 611, 632, 688, 700, 706, 711, 731–733, 746
TOTAL	22208	2760	87%

Python Unit Test Overview

Tests	Skipped	Failures	Errors	Time
4709	247 💤	0 ❌	0 🔥	1m 20s ⏱️

[Copilot]

Pull request overview

Adds regression coverage to ensure declarative workflows correctly initialize Workflow.Inputs at the Entry node so PowerFx expressions referencing inputs.* behave correctly when workflow.run() is invoked with dict or string inputs (fixes #3948 regression risk).

Changes:

• Add a regression test verifying dict inputs populate inputs.age so an If condition routes to the correct branch.
• Add a regression test verifying string inputs populate inputs.input so the value is accessible in expressions.