feat: Add database table for model context length configuration (#477)

* feat: add database table for model context length configuration

- Add model_context table with provider/model/context_limit fields
- Implement UPSERT endpoint for model context configuration
- Add priority lookup: database > config.yaml > custom_providers > cache
- Add frontend click-to-edit UI in ChatInput with tooltip
- Add i18n support for context editing dialog (all 8 locales)
- Use context_limit field consistently across frontend and backend

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

* fix: use useMessage() composable instead of window.$message in ChatInput

- Remove incorrect NMessage import (not a component)
- Use useMessage() composable from naive-ui
- Replace window.$message?.xxx() with message.xxx()
- Fixes TypeScript build errors

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

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/server/src/services/hermes/model-context.ts

@@ -2,6 +2,8 @@ import { resolve, join } from 'path'
 import { homedir } from 'os'
 import { readFileSync, existsSync, statSync } from 'fs'
 import yaml from 'js-yaml'
+import { getDb } from '../../db'
+import { MODEL_CONTEXT_TABLE } from '../../db/hermes/schemas'
 
 const HERMES_BASE = resolve(homedir(), '.hermes')
 const MODELS_DEV_CACHE = resolve(HERMES_BASE, 'models_dev_cache.json')
@@ -234,6 +236,25 @@ function lookupContextFromCache(modelName: string, provider: string | null): num
  *   3. models_dev_cache.json, scoped to model.provider when configured
  *   4. DEFAULT_CONTEXT_LENGTH (200K hardcoded fallback)
  */
+/**
+ * 从数据库 model_context 表查找上下文长度（最高优先级）
+ */
+function lookupContextFromDatabase(modelName: string, provider: string | null): number | null {
+  const db = getDb()
+  if (!db) return null
+
+  try {
+    // 尝试精确匹配 provider 和 model
+    const row = db
+      .prepare(`SELECT context_limit FROM ${MODEL_CONTEXT_TABLE} WHERE provider = ? AND model = ?`)
+      .get(provider || 'default', modelName) as { context_limit: number } | undefined
+
+    return row?.context_limit || null
+  } catch {
+    return null
+  }
+}
+
 export function getModelContextLength(profile?: string): number {
   const profileDir = getProfileDir(profile)
   const config = loadConfig(profileDir)
@@ -242,12 +263,17 @@ export function getModelContextLength(profile?: string): number {
   const model = getDefaultModel(config)
   if (!model) return DEFAULT_CONTEXT_LENGTH
 
+  const provider = getDefaultProvider(config)
+
+  // 0. Database model_context table (highest priority)
+  const dbCtx = lookupContextFromDatabase(model, provider)
+  if (dbCtx && dbCtx > 0) return dbCtx
+
   // 1. Global context_length override in config.yaml
   const configCtx = getConfigContextLength(config)
   if (configCtx && configCtx > 0) return configCtx
 
   // 2. Custom provider context_length
-  const provider = getDefaultProvider(config)
   const customCtx = lookupCustomProviderContextLength(config, model, provider)
   if (customCtx && customCtx > 0) return customCtx