chore: Remove deprecated dead code from Rust runtime

[F16shen]

Summary

• Remove LiteLLMClient and the litellm-rs dependency; production uses LlmClient.
• Remove legacy SystemDiagnoseAgent, create_diagnose_subsession, and ToolRegistry::default_tools.
• Delete superseded state_capture module and unused stubs (mark_prompt_ready, hostname).

Codex/provider/oauth code is intentionally left for a follow-up wiring PR.

Test plan

• make format-check
• make lint
• cargo test -p aish-llm -p aish-tools --lib --tests

Summary by CodeRabbit

• Refactor

  • Consolidated LLM client implementations to use single OpenAI-compatible interface.
  • Removed legacy diagnostic agent and associated system prompts.
  • Simplified internal shell state tracking removal.
  • Streamlined session interceptor by removing unused prompt-ready hooks.
  • Cleaned up tool registry API for improved consistency.

• Chores

  • Removed deprecated dependencies and internal utilities.
  • Updated internal module exports to reflect API simplifications.

[github-actions]

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Contribution guide: https://github.com/AI-Shell-Team/aish/blob/main/CONTRIBUTING.md

[github-actions]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 57aa41ed-5e8e-4f1f-9447-643eac5d2c94

📥 Commits

Reviewing files that changed from the base of the PR and between 4e3b91d and 82c2c19.

📒 Files selected for processing (1)

• crates/aish-llm/tests/llm_integration_test.rs

📝 Walkthrough

Walkthrough

This PR removes deprecated and legacy APIs across three crates. In aish-llm, the litellm-rs dependency, LiteLLMClient, SystemDiagnoseAgent, and LlmSession::create_diagnose_subsession are deleted, with re-exports and integration tests updated for LlmClient. In aish-pty, the entire state_capture module and SessionInterceptor::mark_prompt_ready are removed. In aish-shell, the hostname() helper is dropped. In aish-tools, ToolRegistry::default_tools is replaced with drain_tools.

Changes

aish-llm: LiteLLM → LlmClient and legacy agent removal

Layer / File(s)	Summary
LlmClient replaces LiteLLMClient; re-exports narrowed crates/aish-llm/Cargo.toml, crates/aish-llm/src/client.rs, crates/aish-llm/src/lib.rs	Drops the litellm-rs dependency, removes LiteLLMClient and a stale streaming comment from client.rs, keeps LlmClient, and narrows lib.rs pub use to remove LiteLLMClient and SystemDiagnoseAgent.
Remove SystemDiagnoseAgent and create_diagnose_subsession crates/aish-llm/src/agent.rs, crates/aish-llm/src/session.rs	Deletes SystemDiagnoseAgent (constructors and diagnose method) from agent.rs and removes LlmSession::create_diagnose_subsession from session.rs.
Integration tests updated for LlmClient crates/aish-llm/tests/llm_integration_test.rs	Replaces LiteLLMClient imports and tests with LlmClient construction, API-base trimming, and model-prefix-stripping tests; retains provider detection, DiagnoseAgent, SubSessionConfig, dashboard URL, and tool-support coverage with inline comments removed.

aish-pty state_capture removal, mark_prompt_ready removal, hostname and ToolRegistry cleanup

Layer / File(s)	Summary
Remove state_capture module from aish-pty crates/aish-pty/src/lib.rs, crates/aish-pty/src/state_capture.rs	Removes pub mod state_capture and the StateChanges re-export from lib.rs; state_capture.rs (with StateChanges, create_state_file, detect_changes, apply_changes, and related helpers) is deleted entirely.
Remove mark_prompt_ready from SessionInterceptor and PersistentPty crates/aish-pty/src/session_interceptor.rs, crates/aish-pty/src/persistent.rs	Deletes SessionInterceptor::mark_prompt_ready and removes its call site in PersistentPty::send_command_interactive's idle-threshold branch.
Remove hostname helper and replace ToolRegistry::default_tools with drain_tools crates/aish-shell/src/ai_handler.rs, crates/aish-tools/src/registry.rs	Deletes pub(crate) fn hostname() from ai_handler.rs. Removes ToolRegistry::default_tools() and adds drain_tools(&mut self) which extracts all registered tools as (String, Box<dyn Tool>) pairs, clearing the registry.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• AI-Shell-Team/aish#131: Directly modifies SystemDiagnoseAgent behavior and prompts in crates/aish-llm/src/agent.rs, the same struct this PR removes entirely.
• AI-Shell-Team/aish#152: Works on SessionInterceptor and PersistentPty::send_command_interactive, overlapping with this PR's removal of mark_prompt_ready from those same components.
• AI-Shell-Team/aish#233: Adds Tool::prompt() and centralized prompt metadata, directly related to the tool registration path affected by the ToolRegistry::default_tools → drain_tools replacement.

Poem

🐇 Hop, hop, away with the old!
LiteLLMClient? Gone, I'm told.
state_capture dust, swept from the floor,
mark_prompt_ready knocks no more.
The warren grows tidy, the code runs clear—
A leaner shell, that's why I'm here! 🌿

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main objective of removing deprecated dead code from the Rust runtime, which aligns with all the changes shown.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/aish-llm/tests/llm_integration_test.rs`:
- Around line 84-86: Rename the variable `ollama_provider` to `mistral_provider`
in the test function. The variable is incorrectly named since it actually
contains the result of detecting the Mistral provider (as confirmed by the
assertions checking for "mistral" and "Mistral AI"), not the Ollama provider.
Update the variable name in the assignment and in all subsequent uses within the
assertions to match the consistent naming pattern used for other provider
variables in the test like `openai_provider`, `anthropic_provider`, and
`google_provider`.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 4cd26463-e874-4f5b-85ff-0a8bf4220165

📥 Commits

Reviewing files that changed from the base of the PR and between f1b4061 and 4e3b91d.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (12)

• crates/aish-llm/Cargo.toml
• crates/aish-llm/src/agent.rs
• crates/aish-llm/src/client.rs
• crates/aish-llm/src/lib.rs
• crates/aish-llm/src/session.rs
• crates/aish-llm/tests/llm_integration_test.rs
• crates/aish-pty/src/lib.rs
• crates/aish-pty/src/persistent.rs
• crates/aish-pty/src/session_interceptor.rs
• crates/aish-pty/src/state_capture.rs
• crates/aish-shell/src/ai_handler.rs
• crates/aish-tools/src/registry.rs

💤 Files with no reviewable changes (9)

• crates/aish-shell/src/ai_handler.rs
• crates/aish-pty/src/session_interceptor.rs
• crates/aish-pty/src/state_capture.rs
• crates/aish-llm/src/session.rs
• crates/aish-pty/src/persistent.rs
• crates/aish-tools/src/registry.rs
• crates/aish-pty/src/lib.rs
• crates/aish-llm/src/agent.rs
• crates/aish-llm/Cargo.toml