Consolidated from two separate runners (agent-runner-deno.ts +
agent-runner.ts) to a single pre-built agent-runner.mjs that runs
under both Deno and Node.js. resolve_sidecar_command() now checks
runtime availability upfront before path search, with improved
error messages. Removed agent-runner-deno.ts from tauri.conf.json
bundled resources.
Refactor SidecarManager to use SidecarCommand struct abstracting
runtime choice. resolve_sidecar_command() prefers Deno (runs TS
directly, no build step), falls back to Node.js if deno not in PATH.
Both runners bundled in tauri.conf.json resources. Set auto-update
signing pubkey in updater config.
Build-from-source installer (install-v2.sh) with dependency checks for
Node.js 20+, Rust 1.77+, and system libraries. Tauri bundle config for
.deb and AppImage targets. GitHub Actions workflow builds and uploads
release artifacts on version tags. Icons regenerated as RGBA PNGs.