chore: bump version to 1.8.0 — Codex-inspired chat overhaul

Major chat improvements inspired by OpenAI Codex TUI:
- Exec command cards with output, exit codes, timing
- Inline unified diff review with approve/reject per file
- Context window % always visible in header
- Elapsed time tracker on agent runs
- Shimmer text effect on thinking state
- Shift+Tab mode cycling (Ask → Agent → Plan)
- 30 slash commands with categories
- Cross-session input history (↑/↓ arrows)
- Streaming markdown optimization (debounced parsing)
- Terminal session isolation (terminal:main)

Author: BunsDev

package.json

@@ -1,6 +1,6 @@
 {
   "name": "code-editor",
-  "version": "1.7.0",
+  "version": "1.8.0",
   "private": true,
   "scripts": {
     "frontend:dev": "next dev --turbopack",

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "../node_modules/@tauri-apps/cli/config.schema.json",
   "productName": "KnotCode",
-  "version": "1.7.0",
+  "version": "1.8.0",
   "identifier": "ai.openknot.code-editor",
   "build": {
     "frontendDist": "../out",