step 5 (complete): docs purge, fresh ARCHITECTURE + ROADMAP + CHANGELOG

Purged 29,966 lines of stale chat-switchboard documentation:
  - 41 docs/ files (ICD specs, design docs, archive, workflow docs)
  - 5 root MD files (CHANGESET, TURNOVER, ICD-DRIFT-AUDIT, etc.)

New documentation:
  - docs/ARCHITECTURE.md — kernel components, design principles, data layer
  - ROADMAP.md — v0.1.0 through v0.5.0 MVP with decision log
  - CHANGELOG.md — fresh, starting from v0.1.0 fork
  - README.md — rewritten for switchboard-core

Also in this commit:
  - config.go: stripped 7 dropped fields, DB default → switchboard_core
  - pages/loaders.go: stripped provider/model/notes/projects loaders
  - pages/pages.go: stripped persona store lookup
  - handlers/workflows.go: stripped persona tool grants
  - main.go: stripped team provider routes, avatar routes

Production code: zero references to deleted packages, stores, or models.
-29,966/+352 lines across 73 files.

server/config/config.go

@@ -25,11 +25,6 @@ type Config struct {
 	// Seed users (dev/test only) — CSV: "user:pass:role,user2:pass2:role2"
 	SeedUsers string
 
-	// Seed providers (dev/test only) — CSV: "provider:api_key[:name]"
-	// Shortcuts: "openai:sk-xxx", "anthropic:sk-ant-xxx", "openrouter:sk-or-xxx"
-	// Skips if provider with same name exists (idempotent on restart).
-	SeedProviders string
-
 	// API key encryption (required for v0.9.4+)
 	// Used to derive AES-256 key for global/team provider API keys.
 	// Personal keys use per-user UEK (derived from password).
@@ -51,37 +46,6 @@ type Config struct {
 	S3Prefix         string // optional key prefix within bucket (e.g. "switchboard/")
 	S3ForcePathStyle bool   // use path-style URLs (required for MinIO, most self-hosted)
 
-	// Extraction pipeline (v0.12.0+)
-	// EXTRACTION_MODE: "inline" (in-process) or "sidecar" (shared PVC watcher).
-	// EXTRACTION_CONCURRENCY: max concurrent extraction jobs (default 3).
-	ExtractionMode        string
-	ExtractionConcurrency int
-
-	// Workspace indexing (v0.21.2)
-	// WORKSPACE_INDEXING_ENABLED: global kill switch for workspace file indexing (default true).
-	// WORKSPACE_INDEX_CONCURRENCY: max concurrent indexing goroutines (default 2).
-	WorkspaceIndexingEnabled bool
-	WorkspaceIndexConcurrency int
-
-	// Provider auto-disable (v0.22.4)
-	// PROVIDER_AUTO_DISABLE_THRESHOLD: consecutive "down" hourly windows before a
-	// provider is automatically deactivated. Default 3. Set to 0 to disable.
-	ProviderAutoDisableThreshold int
-
-	// Config-file provider types (v0.29.1)
-	// PROVIDER_TYPES_FILE: path to JSON file defining custom provider types
-	// (e.g., Ollama, LiteLLM, vLLM). Empty = no custom types.
-	ProviderTypesFile string
-
-	// SESSION_EXPIRY_DAYS: anonymous sessions older than this with no messages
-	// are cleaned up by the background session sweeper. Default 30. Set to 0
-	// to disable cleanup.
-	SessionExpiryDays int
-
-	// WORKFLOW_STALE_HOURS: workflow instances with no activity for this many
-	// hours are marked 'stale'. Default 72 (3 days). Set to 0 to disable.
-	WorkflowStaleHours int
-
 	// Structured logging (v0.33.0)
 	// LOG_FORMAT: "text" (default, backward-compatible) or "json" (structured).
 	// LOG_LEVEL: "debug", "info" (default), "warn", "error".
@@ -131,7 +95,6 @@ func Load() *Config {
 		AdminPassword: getEnv("SWITCHBOARD_ADMIN_PASSWORD", ""),
 		AdminEmail:    getEnv("SWITCHBOARD_ADMIN_EMAIL", ""),
 		SeedUsers:     getEnv("SEED_USERS", ""),
-		SeedProviders: getEnv("SEED_PROVIDERS", ""),
 		EncryptionKey: getEnv("ENCRYPTION_KEY", ""),
 
 		StorageBackend:        getEnv("STORAGE_BACKEND", ""),
@@ -143,19 +106,6 @@ func Load() *Config {
 		S3SecretKey:           getEnv("S3_SECRET_KEY", ""),
 		S3Prefix:              getEnv("S3_PREFIX", ""),
 		S3ForcePathStyle:      getEnv("S3_FORCE_PATH_STYLE", "true") == "true",
-		ExtractionMode:        getEnv("EXTRACTION_MODE", "inline"),
-		ExtractionConcurrency: getEnvInt("EXTRACTION_CONCURRENCY", 3),
-
-		WorkspaceIndexingEnabled:  getEnvBool("WORKSPACE_INDEXING_ENABLED", true),
-		WorkspaceIndexConcurrency: getEnvInt("WORKSPACE_INDEX_CONCURRENCY", 2),
-
-		ProviderAutoDisableThreshold: getEnvInt("PROVIDER_AUTO_DISABLE_THRESHOLD", 3),
-
-		ProviderTypesFile: getEnv("PROVIDER_TYPES_FILE", ""),
-
-		SessionExpiryDays: getEnvInt("SESSION_EXPIRY_DAYS", 30),
-
-		WorkflowStaleHours: getEnvInt("WORKFLOW_STALE_HOURS", 72),
 
 		LogFormat: getEnv("LOG_FORMAT", "text"),
 		LogLevel:  getEnv("LOG_LEVEL", "info"),
@@ -205,7 +155,7 @@ func resolveDatabaseURL() string {
 	port := getEnv("POSTGRES_PORT", "5432")
 	user := getEnv("POSTGRES_USER", "")
 	pass := getEnv("POSTGRES_PASSWORD", "")
-	db := getEnv("POSTGRES_DB", "chat_switchboard")
+	db := getEnv("POSTGRES_DB", "switchboard_core")
 	ssl := getEnv("POSTGRES_SSLMODE", "disable")
 	return fmt.Sprintf("postgres://%s:%s@%s:%s/%s?sslmode=%s", user, pass, host, port, db, ssl)
 }