fix(goose): only send agent-session-id when a session exists

[codefromthecrypt]

Summary

Stop adding the agent-session-id header unless there is a current session. This keeps headers 1:1 with session manager records and avoids confusing or conflicting session IDs.

None is for configuration or pre-session paths (model discovery, provider detection, auth probes, canonical model checks).

This also backfills propagation of non-basic OpenAI apis so they can also see agent-session-id (e.g., Anthropic, Bedrock, Vertex etc). This is important because proxies like Envoy AI Gateway and Ollama started supporting non-OpenAI endpoints recently. With this, they can do log correlation on goose session ID.

Type of Change

• Feature
• Bug fix
• Refactor / Code quality
• Tests
• Performance improvement
• Documentation
• Security fix
• Build / Release
• Other (specify below)

AI Assistance

• This PR was created or reviewed with AI assistance

Testing

Added some edge case tests.

Related Issues

Tuneup of #6626

[codefromthecrypt]

this is the key place though some others had to switch to Option to support pre-session tasks

[Copilot]

Pull request overview

Stops propagating agent-session-id unless a real goose session exists, while ensuring non-OpenAI-compatible providers can still receive the header for correlation when a session does exist.

Changes:

• Updates the provider completion path to accept session_id: Option<&str> and only inject agent-session-id when Some(non_empty).
• Removes session-id requirements from model discovery/config/probing paths (fetch_supported_models / fetch_recommended_models) and updates call sites accordingly.
• Adds/updates tests to cover header injection/removal behavior and MCP session propagation edge cases.

Reviewed changes

Copilot reviewed 36 out of 36 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/goose/tests/mcp_integration_test.rs	Updates mock provider signature to accept optional session id.
crates/goose/tests/agent.rs	Adapts test provider to optional session id for completion.
crates/goose/src/providers/xai.rs	Threads optional session id through completion requests.
crates/goose/src/providers/venice.rs	Removes session requirement for model fetch; optional session for completion.
crates/goose/src/providers/tetrate.rs	Removes session requirement for model fetch; optional session for completion.
crates/goose/src/providers/testprovider.rs	Propagates optional session id through wrapped provider calls.
crates/goose/src/providers/snowflake.rs	Threads optional session id through requests.
crates/goose/src/providers/sagemaker_tgi.rs	Conditionally propagates session id via SageMaker custom attributes.
crates/goose/src/providers/openrouter.rs	Removes session requirement for model fetch; conditional session propagation via payload/user + header.
crates/goose/src/providers/openai.rs	Removes session requirement for model fetch; optional session for completion calls.
crates/goose/src/providers/ollama.rs	Removes session requirement for model fetch; optional session for completion.
crates/goose/src/providers/litellm.rs	Removes session requirement for model fetch; optional session for completion + cache-control detection.
crates/goose/src/providers/lead_worker.rs	Updates delegation to use complete_with_model with optional session id; removes session from model fetch.
crates/goose/src/providers/google.rs	Removes session requirement for model fetch; optional session propagation for requests/streaming.
crates/goose/src/providers/githubcopilot.rs	Removes session requirement for model fetch; optional session propagation for requests.
crates/goose/src/providers/gemini_cli.rs	Updates provider signature to optional session id (still ignored for CLI).
crates/goose/src/providers/gcpvertexai.rs	Conditionally injects session header for Vertex AI requests; removes session from model fetch.
crates/goose/src/providers/databricks.rs	Removes pre-session UUID generation for probing; removes session requirement for model fetch; optional session for completion.
crates/goose/src/providers/cursor_agent.rs	Updates provider signature to optional session id (still ignored for CLI).
crates/goose/src/providers/codex.rs	Updates provider signature to optional session id (still ignored for CLI).
crates/goose/src/providers/claude_code.rs	Updates provider signature to optional session id (still ignored for CLI constraints).
crates/goose/src/providers/chatgpt_codex.rs	Conditionally injects agent-session-id header for streaming requests; removes session from model fetch.
crates/goose/src/providers/canonical/build_canonical_models.rs	Removes pre-session UUID generation for provider probing/model fetch.
crates/goose/src/providers/bedrock.rs	Conditionally injects agent-session-id header into AWS Bedrock requests.
crates/goose/src/providers/base.rs	Changes provider trait APIs to use optional session id for completion and removes session from model fetch APIs.
crates/goose/src/providers/azure.rs	Threads optional session id through requests.
crates/goose/src/providers/auto_detect.rs	Removes pre-session UUID usage; uses sessionless model fetch for provider detection.
crates/goose/src/providers/api_client.rs	Makes request builder session-aware (optional) and adds tests for header set/replace/remove behavior.
crates/goose/src/providers/anthropic.rs	Removes session requirement for model fetch; optional session for completion; ensures streaming still passes session.
crates/goose/src/context_mgmt/mod.rs	Updates test provider signature to optional session id.
crates/goose/src/agents/reply_parts.rs	Updates test provider signature to optional session id.
crates/goose/src/agents/mcp_client.rs	Removes connection-scoped fallback session id; makes MCP session id propagation optional and removable.
crates/goose/examples/image_tool.rs	Updates example to use complete_with_model(None, ...) for pre-session usage.
crates/goose/examples/databricks_oauth.rs	Updates example to use complete_with_model(None, ...) for pre-session usage.
crates/goose-server/src/routes/config_management.rs	Removes pre-session UUID generation; uses sessionless model fetch/provider detect.
crates/goose-cli/src/commands/configure.rs	Removes pre-session UUID generation; switches config checks to sessionless model fetch or complete_with_model(None, ...).

Comments suppressed due to low confidence (1)

crates/goose/examples/image_tool.rs:71

• &provider.get_model_config() borrows a temporary ModelConfig across .await, which will not compile; assign let model_config = provider.get_model_config(); before the call and pass &model_config.

        let (response, usage) = provider
            .complete_with_model(
                None,
                &provider.get_model_config(),
                "You are a helpful assistant. Please describe any text you see in the image.",
                &messages,
                &[Tool::new("view_image", "View an image", input_schema)],
            )