feat: support runtime system prompt interpolation in advanced agents

[andreitava-uip]

Summary

• accept callable system prompts in create_advanced_agent_graph and resolve them once from invocation inputs
• carry the resolved prompt through dynamically declared graph state and prepend it to each Deep Agents model request
• preserve the prepared Deep Agents prompt content blocks, prompt ordering, and cache metadata
• avoid input-schema collisions by using uipath__system_prompt by default and selecting the first available deterministic suffix
• bump uipath-langchain to 0.14.20

Verification

• uv lock --check
• Ruff format and lint
• mypy on changed implementation and tests
• targeted advanced-agent and workspace-memory tests (16 passed)
• manual local validation

[Copilot]

Pull request overview

Adds support for runtime-interpolated system prompts in the advanced-agent wrapper graph by allowing system_prompt to be provided as a callable, resolving it once from invocation inputs, and injecting it into Deep Agents model requests via middleware while avoiding input-schema key collisions.

Changes:

• Accept callable system_prompt in create_advanced_agent_graph, resolve it during transform_input, and carry it via a dynamically-extended graph state key.
• Introduce _RuntimeSystemPromptMiddleware and _allocate_runtime_system_prompt_key to prepend runtime prompts to each model request and avoid schema/alias collisions deterministically.
• Update tests to cover runtime prompt resolution, collision avoidance, request prepending behavior, and async middleware handling; bump package version to 0.14.20.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/uipath_langchain/agent/advanced/agent.py	Adds runtime system-prompt middleware, state-key allocation logic, and callable system-prompt support in the advanced agent wrapper graph.
tests/agent/advanced/test_create_advanced_agent_graph.py	Adds test coverage for callable system prompts, collision handling, middleware request prepending, and async paths.
pyproject.toml	Bumps project version to 0.14.20.
uv.lock	Updates locked package version to 0.14.20.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
94.1% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud