Improve workflow authoring and runtime controls

[philbotar]

Summary

• bring workflow authoring onto the shared runtime/composer controls, keep mutation intent through clarification, add a visible cancel path
• accept live user messages during active conversation/tool turns, harden run stop plus Bash/PTY descendant cleanup
• share login-shell PATH across Terminal, Bash, MCP probes/installs/runs; add read-tier ls plus safe find handling
• improve MCP OAuth retry/discovery diagnostics, project/chat detachment, persisted chat approval defaults
• bump changed package versions: engine 0.1.15, orchestration 0.1.30, UI 0.1.26

Why

Several user-facing seams diverged: authoring used reduced runtime controls, queued input did not reliably reach the next model turn, cancellation could leave subprocess descendants alive, GUI-launched tools could not resolve the user's shell-installed runtimes, and the version gate saw substantive crate changes without matching package bumps.

Impact

Authoring now retains full runtime config with explicit cancellation. Active chats accept follow-up input safely. Stop terminates real command processes. Terminal/Bash/MCP resolve the same user environment. Safe filesystem inspection requires fewer approval prompts. MCP OAuth failures expose actionable retry state.

Testing

• ./scripts/verify.sh — PASS 11/11
• ./scripts/check-version-bump.sh
• ./scripts/check-release-version.sh
• cargo metadata --locked --no-deps --format-version 1
• git diff --check

Release

• Bumped library/package versions for substantive changes
• Desktop app version unchanged; this is a feature PR, not a release cut