step 5 (partial): strip dropped packages from production code

Removed all references to dropped packages in non-test code.
Zero dropped imports, store refs, or model types remaining.

Major removals:
  - scheduler/ package (entire dir) — tasks moved to extension track
  - taskutil/ package (entire dir)
  - health/ package (entire dir) — provider/tool health
  - sandbox/provider_module.go — provider.complete module
  - handlers: workflow_entry, workflow_instances, workflow_forms,
    workflow_assignments, workflow_monitor, health_admin (6 files)
  - auth/session.go, middleware/session_auth.go
  - store/{postgres,sqlite}/sessions.go, tasks.go

Rewrites:
  - store/{postgres,sqlite}/health.go — kernel-only Prune
    (ws_tickets, rate_limit_counters, stale presence)
  - handlers/admin.go: 847→467 lines (stripped provider CRUD)
  - handlers/teams.go: 520→411 lines (stripped model listing)
  - sandbox/runner.go: removed ProviderResolver
  - sandbox/workflow_module.go: 216→83 lines (definition-only)
  - main.go: 1579→1325 lines (stripped dropped package init)
  - pages/pages.go: stripped channel/session lookups
  - events/types.go: stripped chat/channel/workspace event routes
  - models: stripped stale types, constants, notification types

Store interface cleanup:
  - Removed SessionStore, TaskStore from Stores struct
  - Stripped workflow assignment methods from WorkflowStore iface
  - Stripped assignment methods from PG+SQLite workflow stores
  - Updated testhelper.go table list to kernel-only

Migrations: removed 008_tasks.sql (both dialects)

-9665/+69 lines across 51 files.

server/models/models.go

@@ -369,25 +369,9 @@ type ResourceGrant struct {
 // ProviderStatus represents the derived health state.
 
 // AvgLatencyMs returns the average latency, or 0 if no requests.
-func (w *ProviderHealthWindow) AvgLatencyMs() int {
-	if w.RequestCount == 0 {
-		return 0
-	}
-	return int(w.TotalLatencyMs / int64(w.RequestCount))
-}
 
 // ErrorRate returns the error fraction, or 0 if no requests.
-func (w *ProviderHealthWindow) ErrorRate() float64 {
-	if w.RequestCount == 0 {
-		return 0
-	}
-	return float64(w.ErrorCount) / float64(w.RequestCount)
-}
 
-// ProviderHealthSummary is the API response for a provider's current health.
-// ToolHealthWindow tracks health of built-in tools (web_search, url_fetch, etc.)
-// in hourly buckets, analogous to ProviderHealthWindow.
-// ToolHealthSummary is the API response for a tool's health.
 // CAPABILITY OVERRIDES (v0.22.0)
 
 // CapabilityOverride is an admin correction for a model's capabilities.

server/models/models_extension_perm.go

@@ -28,11 +28,9 @@ var ValidPackageStatuses = map[string]bool{
 const (
 	ExtPermSecretsRead          = "secrets.read"
 	ExtPermNotificationsSend    = "notifications.send"
-	ExtPermFiltersPreCompletion = "filters.pre_completion"
 	ExtPermDBRead               = "db.read"
 	ExtPermDBWrite              = "db.write"
 	ExtPermAPIHTTP              = "api.http"
-	ExtPermProviderComplete     = "provider.complete"  // v0.29.1: LLM completion calls
 	ExtPermFormValidate         = "forms.validate"    // v0.29.3: form validation hooks
 	ExtPermWorkflowAccess       = "workflow.access"   // v0.30.2: workflow definition + stage data access
 	ExtPermConnectionsRead      = "connections.read"  // v0.38.1: extension connection resolution
@@ -42,11 +40,9 @@ const (
 var ValidExtensionPermissions = map[string]bool{
 	ExtPermSecretsRead:          true,
 	ExtPermNotificationsSend:    true,
-	ExtPermFiltersPreCompletion: true,
 	ExtPermDBRead:               true,
 	ExtPermDBWrite:              true,
 	ExtPermAPIHTTP:              true,
-	ExtPermProviderComplete:     true,
 	ExtPermFormValidate:         true,
 	ExtPermWorkflowAccess:       true,
 	ExtPermConnectionsRead:      true,

server/models/models_notification.go

@@ -27,7 +27,6 @@ const (
 	NotifTypeKBReady         = "kb.ready"
 	NotifTypeKBError         = "kb.error"
 	NotifTypeGrantChanged    = "grant.changed"
-	NotifTypeMemoryExtracted = "memory.extracted"
 	NotifTypeUserMentioned   = "user.mentioned"
 	NotifTypeWorkflowAssign  = "workflow.assigned"
 	NotifTypeWorkflowClaimed = "workflow.claimed"

server/models/models_task.go

@@ -1,99 +0,0 @@
-package models
-
-import (
-	"encoding/json"
-	"time"
-)
-
-// Task is a scheduled, one-shot, or webhook-triggered job that creates a
-// service channel and runs a completion (prompt task), instantiates a
-// workflow, relays a payload without LLM involvement (action task), or
-// executes a built-in Go function (system task).
-type Task struct {
-	ID          string  `json:"id" db:"id"`
-	OwnerID     string  `json:"owner_id" db:"owner_id"`
-	TeamID      *string `json:"team_id,omitempty" db:"team_id"`
-	Name        string  `json:"name" db:"name"`
-	Description string  `json:"description" db:"description"`
-	Scope       string  `json:"scope" db:"scope"` // personal | team | global
-
-	// What to run
-	TaskType       string           `json:"task_type" db:"task_type"` // prompt | workflow | action | system
-	SystemFunction string           `json:"system_function,omitempty" db:"system_function"`
-	PersonaID   *string          `json:"persona_id,omitempty" db:"persona_id"`
-	ModelID     string           `json:"model_id" db:"model_id"`
-	SystemPrompt string          `json:"system_prompt" db:"system_prompt"`
-	UserPrompt  string           `json:"user_prompt" db:"user_prompt"`
-	WorkflowID  *string          `json:"workflow_id,omitempty" db:"workflow_id"`
-	ToolGrants  json.RawMessage  `json:"tool_grants,omitempty" db:"tool_grants"`
-
-	// Schedule
-	Schedule string `json:"schedule" db:"schedule"` // cron expression, "once", or "webhook"
-	Timezone string `json:"timezone" db:"timezone"`
-	IsActive bool   `json:"is_active" db:"is_active"`
-
-	// Webhook trigger (inbound)
-	TriggerToken string `json:"trigger_token,omitempty" db:"trigger_token"`
-
-	// Execution policy
-	MaxTokens    int    `json:"max_tokens" db:"max_tokens"`
-	MaxToolCalls int    `json:"max_tool_calls" db:"max_tool_calls"`
-	MaxWallClock int    `json:"max_wall_clock" db:"max_wall_clock"` // seconds
-	OutputMode   string `json:"output_mode" db:"output_mode"`       // channel | note | webhook
-	OutputChannelID *string `json:"output_channel_id,omitempty" db:"output_channel_id"`
-	WebhookURL    string `json:"webhook_url" db:"webhook_url"`
-	WebhookSecret string `json:"webhook_secret,omitempty" db:"webhook_secret"`
-
-	// Provider routing
-	ProviderConfigID *string `json:"provider_config_id,omitempty" db:"provider_config_id"`
-
-	// Notifications
-	NotifyOnComplete bool `json:"notify_on_complete" db:"notify_on_complete"`
-	NotifyOnFailure  bool `json:"notify_on_failure" db:"notify_on_failure"`
-
-	// Bookkeeping
-	LastRunAt  *time.Time `json:"last_run_at,omitempty" db:"last_run_at"`
-	NextRunAt  *time.Time `json:"next_run_at,omitempty" db:"next_run_at"`
-	RunCount   int        `json:"run_count" db:"run_count"`
-	CreatedAt  time.Time  `json:"created_at" db:"created_at"`
-	UpdatedAt  time.Time  `json:"updated_at" db:"updated_at"`
-}
-
-// TaskPatch contains optional fields for updating a task.
-type TaskPatch struct {
-	Name             *string          `json:"name,omitempty"`
-	Description      *string          `json:"description,omitempty"`
-	PersonaID        *string          `json:"persona_id,omitempty"`
-	ModelID          *string          `json:"model_id,omitempty"`
-	SystemPrompt     *string          `json:"system_prompt,omitempty"`
-	UserPrompt       *string          `json:"user_prompt,omitempty"`
-	WorkflowID       *string          `json:"workflow_id,omitempty"`
-	ToolGrants       *json.RawMessage `json:"tool_grants,omitempty"`
-	Schedule         *string          `json:"schedule,omitempty"`
-	Timezone         *string          `json:"timezone,omitempty"`
-	IsActive         *bool            `json:"is_active,omitempty"`
-	MaxTokens        *int             `json:"max_tokens,omitempty"`
-	MaxToolCalls     *int             `json:"max_tool_calls,omitempty"`
-	MaxWallClock     *int             `json:"max_wall_clock,omitempty"`
-	OutputMode       *string          `json:"output_mode,omitempty"`
-	OutputChannelID  *string          `json:"output_channel_id,omitempty"`
-	WebhookURL       *string          `json:"webhook_url,omitempty"`
-	ProviderConfigID *string          `json:"provider_config_id,omitempty"`
-	NotifyOnComplete *bool            `json:"notify_on_complete,omitempty"`
-	NotifyOnFailure  *bool            `json:"notify_on_failure,omitempty"`
-}
-
-// TaskRun records a single execution of a task.
-type TaskRun struct {
-	ID              string     `json:"id" db:"id"`
-	TaskID          string     `json:"task_id" db:"task_id"`
-	ChannelID       *string    `json:"channel_id,omitempty" db:"channel_id"`
-	Status          string     `json:"status" db:"status"` // queued | running | completed | failed | budget_exceeded | cancelled
-	TriggerPayload  string     `json:"trigger_payload,omitempty" db:"trigger_payload"`
-	StartedAt       time.Time  `json:"started_at" db:"started_at"`
-	CompletedAt     *time.Time `json:"completed_at,omitempty" db:"completed_at"`
-	TokensUsed      int        `json:"tokens_used" db:"tokens_used"`
-	ToolCalls       int        `json:"tool_calls" db:"tool_calls"`
-	WallClock       int        `json:"wall_clock" db:"wall_clock"` // seconds
-	Error           string     `json:"error,omitempty" db:"error"`
-}

server/models/workflow.go

@@ -57,7 +57,7 @@ type WorkflowStage struct {
 	PersonaID        *string         `json:"persona_id,omitempty"`
 	AssignmentTeamID *string         `json:"assignment_team_id,omitempty"`
 	FormTemplate     json.RawMessage `json:"form_template"`
-	StageMode        string          `json:"stage_mode"`   // chat_only | form_only | form_chat | review
+	StageMode        string          `json:"stage_mode"`   // form_only | form_chat | review | custom
 	HistoryMode      string          `json:"history_mode"` // full | summary | fresh
 	AutoTransition   bool            `json:"auto_transition"`
 	TransitionRules  json.RawMessage `json:"transition_rules"`
@@ -69,7 +69,7 @@ type WorkflowStage struct {
 // ── Stage Mode Constants ────────────────────
 
 const (
-	StageModeChatOnly = "chat_only"
+	StageModeCustom   = "custom"
 	StageModeFormOnly = "form_only"
 	StageModeFormChat = "form_chat"
 	StageModeReview   = "review"
@@ -77,7 +77,7 @@ const (
 
 // ValidStageModes is the set of valid stage_mode values.
 var ValidStageModes = map[string]bool{
-	StageModeChatOnly: true,
+	StageModeCustom:   true,
 	StageModeFormOnly: true,
 	StageModeFormChat: true,
 	StageModeReview:   true,