Sessions (tab list with sessionId, iframeUrl, activeIndex) are now
saved to plugin data on every mutation (add/close/switch) and restored
when the view reopens after an Obsidian restart. Falls back to creating
a new session if no saved data exists.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

New language setting (en/zh) with full i18n support for all settings
UI text. Language selector placed at the top of the settings page;
switching instantly re-renders the page in the chosen language.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Polls GET /session/status every 5 seconds when the server is running.
- Ribbon icon pulses with accent color when any session is busy/retrying
- Tab bar shows busy (pulsing) or attention (red) state per session
- Gracefully starts/stops polling with server lifecycle

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bilingual README with Chinese as primary language. Added fork-specific
feature descriptions (multi-session tabs, session persistence, i18n
settings, real-time status indicator). Updated BRAT install path to
nthforsth/opencode-obsidian.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Add killZombieOnPort() in ServerManager: detect unresponsive process
  on the configured port and auto-kill it before spawning a new server
- Simplify WindowsProcess.stop(): use taskkill /F /T for reliable
  process tree termination instead of manual PowerShell child lookup
- Simplify WindowsProcess.killProcessSync(): same /T flag improvement
- Add static findPidOnPort/killPid helpers for both Windows/Posix
- Remove unused dependencies from ContextManager and ViewManager
  (client, getCachedIframeUrl, setCachedIframeUrl, ensureSessionUrl)
- Rename plugin id to 'opencodian'

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Add listSessions() and deleteSession() to OpenCodeClient for
  server-side session management via REST API
- Add SessionInfo type for session metadata
- Add history button (clock icon) to tab bar
- Add history panel overlay showing all past sessions sorted by time
- Allow loading any historical session into a new tab with one click
- Allow bulk cleanup of old sessions (excluding currently open ones)
- Show relative timestamps (刚刚/X分钟前/X小时前/X天前)
- Mark currently active sessions with accent dot indicator

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The tab bar has overflow-x: auto which clips absolutely positioned
children. Move the panel from tabBarEl to contentEl and position it
with top: 36px so it appears below the tab bar without being clipped.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

When the opencode process dies but the OS kernel still holds the TCP
socket (orphan socket), the previous cleanup logic failed because:
- findPidOnPort returns a stale PID from the dead process
- taskkill fails since the process no longer exists
- New opencode process can't bind to the occupied port

Changes:
- Add processExists() to WindowsProcess and PosixProcess to detect
  dead processes vs orphan sockets
- Add findAvailablePort() for automatic port fallback
- Improve killZombieOnPort() with two-phase strategy:
  1. If process alive → kill + wait 5s
  2. If process dead (orphan socket) → wait up to 15s for OS release
  3. If port still stuck → auto-switch to next available port
- Emit "portChanged" event to persist the new port and update views

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>