feat(server): hot-reload config store and reloadable infra clients

- Replace single Load() with a watching Store that re-reads config files
  (and config.local.yaml) and fans out a ReloadEvent with a per-field diff
  so consumers can decide whether the change is hot-applicable or requires
  a process restart.
- Wrap llm, retrieval, vector store, and object storage clients in
  Reloadable* shells so the bootstrap can swap their underlying impls when
  config changes without re-instantiating handlers.
- Make jwt.Manager and ops TokenIssuer mutable under a lock so secrets and
  TTLs can be rotated live; thread default plan code through a setter on
  the ops AdminUserService.
- Wire ConfigStore through bootstrap and every cmd/main.go, scheduler /
  worker / tenant-api / ops-api start the watcher; services and handlers
  take a config.Provider so they always read current values for things
  like generation.stream_enabled, scheduler dispatch, retrieval, etc.
- Switch shared/config decoding off viper to a Kratos-derived runtime
  package so env placeholders (\${VAR:default}) resolve consistently and
  the same source machinery powers both the loader and the watcher.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/aliyun/aliyun-oss-go-sdk v3.0.2+incompatible
 	github.com/chai2010/webp v1.4.0
 	github.com/extrame/xls v0.0.1
+	github.com/fsnotify/fsnotify v1.7.0
 	github.com/gin-gonic/gin v1.9.1
 	github.com/golang-jwt/jwt/v5 v5.2.1
 	github.com/google/uuid v1.6.0
@@ -15,6 +16,7 @@ require (
 	github.com/ledongthuc/pdf v0.0.0-20240314090751-a2a84ec735c3
 	github.com/lionsoul2014/ip2region/binding/golang v0.0.0-20260428110050-fedf5aaf0308
 	github.com/minio/minio-go/v7 v7.0.83
+	github.com/mitchellh/mapstructure v1.5.0
 	github.com/prometheus/client_golang v1.20.5
 	github.com/prometheus/common v0.60.1
 	github.com/qdrant/go-client v1.13.0
@@ -22,7 +24,6 @@ require (
 	github.com/redis/go-redis/v9 v9.5.1
 	github.com/robfig/cron/v3 v3.0.1
 	github.com/sergi/go-diff v1.4.0
-	github.com/spf13/viper v1.18.2
 	github.com/stretchr/testify v1.9.0
 	github.com/volcengine/volcengine-go-sdk v1.2.22
 	github.com/xuri/excelize/v2 v2.8.1
@@ -43,7 +44,6 @@ require (
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/extrame/ole2 v0.0.0-20160812065207-d69429661ad7 // indirect
-	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.2 // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
 	github.com/go-ini/ini v1.67.0 // indirect
@@ -51,7 +51,6 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.14.0 // indirect
 	github.com/goccy/go-json v0.10.4 // indirect
-	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
 	github.com/jackc/puddle/v2 v2.2.1 // indirect
@@ -60,10 +59,8 @@ require (
 	github.com/klauspost/compress v1.17.11 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.9 // indirect
 	github.com/leodido/go-urn v1.2.4 // indirect
-	github.com/magiconair/properties v1.8.10 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/minio/md5-simd v1.1.2 // indirect
-	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
@@ -75,13 +72,6 @@ require (
 	github.com/richardlehane/mscfb v1.0.4 // indirect
 	github.com/richardlehane/msoleps v1.0.3 // indirect
 	github.com/rs/xid v1.6.0 // indirect
-	github.com/sagikazarmark/locafero v0.4.0 // indirect
-	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
-	github.com/sourcegraph/conc v0.3.0 // indirect
-	github.com/spf13/afero v1.11.0 // indirect
-	github.com/spf13/cast v1.6.0 // indirect
-	github.com/spf13/pflag v1.0.5 // indirect
-	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.11 // indirect
 	github.com/volcengine/volc-sdk-golang v1.0.23 // indirect
@@ -90,13 +80,11 @@ require (
 	github.com/yuin/gopher-lua v1.1.1 // indirect
 	go.uber.org/multierr v1.10.0 // indirect
 	golang.org/x/arch v0.3.0 // indirect
-	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
 	golang.org/x/sys v0.28.0 // indirect
 	golang.org/x/text v0.21.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20240827150818-7e3bb234dfed // indirect
 	google.golang.org/grpc v1.66.0 // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
-	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )