feat(core): implement plugin fiber state machine and reactive dependency reconciler

backend/core/app.go

@@ -77,6 +77,8 @@ type App struct {
 	profile         Profile
 	plugins         []Plugin
 	pluginMap       map[string]Plugin
+	fibers          []*Fiber
+	fiberMap        map[string]*Fiber
 	applied         bool
 	running         bool
 	startedDrivers  []Driver
@@ -90,6 +92,7 @@ func NewApp(opts ...AppOption) *App {
 		ctx:             NewContext(context.Background()),
 		profile:         ProfileAll,
 		pluginMap:       make(map[string]Plugin),
+		fiberMap:        make(map[string]*Fiber),
 		shutdownTimeout: defaultShutdownTimeout,
 	}
 
@@ -149,8 +152,14 @@ func (a *App) Use(plugins ...Plugin) *App {
 					break
 				}
 			}
+			if existingFiber, ok := a.fiberMap[name]; ok {
+				existingFiber.plugin = p
+			}
 		} else {
 			a.plugins = append(a.plugins, p)
+			f := NewFiber(a.ctx, p)
+			a.fibers = append(a.fibers, f)
+			a.fiberMap[name] = f
 		}
 		a.pluginMap[name] = p
 	}
@@ -177,6 +186,25 @@ func (a *App) Plugin(name string) (Plugin, bool) {
 	return p, ok
 }
 
+// Fibers returns a copy of all plugin Fibers.
+func (a *App) Fibers() []*Fiber {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+
+	res := make([]*Fiber, len(a.fibers))
+	copy(res, a.fibers)
+	return res
+}
+
+// Fiber retrieves a Fiber by its unique plugin name.
+func (a *App) Fiber(name string) (*Fiber, bool) {
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+
+	f, ok := a.fiberMap[name]
+	return f, ok
+}
+
 // SetMigrationEngine sets the migration engine for the application.
 func (a *App) SetMigrationEngine(engine MigrationEngine) *App {
 	a.mu.Lock()
@@ -190,7 +218,44 @@ func (a *App) SetMigrationRunner(runner MigrationRunner) *App {
 	return a.SetMigrationEngine(runner)
 }
 
-// ApplyPlugins applies all registered plugins on the application Context.
+// Reconcile evaluates all pending Fibers and reactively transitions them to ACTIVE
+// as their declared dependencies become satisfied.
+func (a *App) Reconcile() error {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return a.reconcileLocked()
+}
+
+func (a *App) reconcileLocked() error {
+	for {
+		progress := false
+		for _, f := range a.fibers {
+			if f.State() == FiberPending && f.DependenciesSatisfied(a.ctx) {
+				if err := f.Load(); err != nil {
+					return fmt.Errorf("core: load fiber %q failed: %w", f.Name(), err)
+				}
+				progress = true
+			}
+		}
+		if !progress {
+			break
+		}
+	}
+
+	var unsatisfied []string
+	for _, f := range a.fibers {
+		if f.State() == FiberPending {
+			unsatisfied = append(unsatisfied, fmt.Sprintf("%s (waiting for %v)", f.Name(), f.Dependencies()))
+		}
+	}
+	if len(unsatisfied) > 0 {
+		return fmt.Errorf("core: unsatisfied dependencies for plugins: %s", strings.Join(unsatisfied, ", "))
+	}
+
+	return nil
+}
+
+// ApplyPlugins applies all registered plugins on the application Context via reactive reconciliation.
 // It is idempotent and only applies plugins once per App instance.
 func (a *App) ApplyPlugins() error {
 	a.mu.Lock()
@@ -199,16 +264,9 @@ func (a *App) ApplyPlugins() error {
 		return nil
 	}
 	a.applied = true
-	plugins := make([]Plugin, len(a.plugins))
-	copy(plugins, a.plugins)
 	a.mu.Unlock()
 
-	for _, p := range plugins {
-		if err := p.Apply(a.ctx); err != nil {
-			return fmt.Errorf("core: apply plugin %q failed: %w", p.Name(), err)
-		}
-	}
-	return nil
+	return a.Reconcile()
 }
 
 // RunMigrations dispatches migration execution across all registered plugin migration entries.
@@ -363,7 +421,19 @@ func (a *App) Stop(ctx ...context.Context) error {
 		}
 	}
 
-	// 2. Dispose context
+	// 2. Unload fibers in reverse order
+	a.mu.RLock()
+	fibers := make([]*Fiber, len(a.fibers))
+	copy(fibers, a.fibers)
+	a.mu.RUnlock()
+
+	for i := len(fibers) - 1; i >= 0; i-- {
+		if err := fibers[i].Unload(); err != nil {
+			errs = append(errs, fmt.Errorf("core: unload fiber %s failed: %w", fibers[i].Name(), err))
+		}
+	}
+
+	// 3. Dispose root context
 	if a.ctx != nil && !a.ctx.IsDisposed() {
 		if err := a.ctx.Dispose(); err != nil {
 			errs = append(errs, fmt.Errorf("core: dispose context failed: %w", err))

backend/core/container.go

@@ -46,7 +46,7 @@ func (c *Container) remove(targetType reflect.Type) {
 	delete(c.services, targetType)
 }
 
-// Provide registers a typed service implementation into the Context's IoC container.
+// Provide registers a typed service implementation into the Context hierarchy's root IoC container.
 func Provide[T any](ctx *Context, service T) {
 	if ctx == nil {
 		panic("core: nil context provided to Provide")
@@ -55,6 +55,25 @@ func Provide[T any](ctx *Context, service T) {
 		panic("core: cannot provide nil service")
 	}
 
+	targetType := reflect.TypeFor[T]()
+	targetContainer := ctx.Root().Container()
+	targetContainer.provide(targetType, service)
+
+	ctx.OnDispose(func() error {
+		targetContainer.remove(targetType)
+		return nil
+	})
+}
+
+// ProvideScoped registers a typed service implementation strictly in the local Context container.
+func ProvideScoped[T any](ctx *Context, service T) {
+	if ctx == nil {
+		panic("core: nil context provided to ProvideScoped")
+	}
+	if isNil(service) {
+		panic("core: cannot provide nil service")
+	}
+
 	targetType := reflect.TypeFor[T]()
 	targetContainer := ctx.Container()
 	targetContainer.provide(targetType, service)

backend/core/context.go

@@ -134,6 +134,15 @@ func (c *Context) Parent() *Context {
 	return c.parent
 }
 
+// Root returns the root Context in the hierarchy.
+func (c *Context) Root() *Context {
+	curr := c
+	for curr.parent != nil {
+		curr = curr.parent
+	}
+	return curr
+}
+
 // Fork creates a child Context with its own scoped IoC container and values,
 // linked to this Context for hierarchical fallback resolution and cascading teardown.
 func (c *Context) Fork() *Context {
@@ -337,15 +346,28 @@ func (c *Context) IsDisposed() bool {
 	return c.disposed
 }
 
-// RegisterDriver registers a runtime driver engine on this Context.
+// RegisterDriver registers a runtime driver engine on this Context hierarchy.
 func (c *Context) RegisterDriver(d Driver) error {
 	if d == nil {
 		return ErrNilService
 	}
 
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	c.drivers = append(c.drivers, d)
+	root := c.Root()
+	root.mu.Lock()
+	root.drivers = append(root.drivers, d)
+	root.mu.Unlock()
+
+	c.OnDispose(func() error {
+		root.mu.Lock()
+		defer root.mu.Unlock()
+		for i, drv := range root.drivers {
+			if drv == d {
+				root.drivers = append(root.drivers[:i], root.drivers[i+1:]...)
+				break
+			}
+		}
+		return nil
+	})
 	return nil
 }
 

backend/core/context_test.go

@@ -238,14 +238,14 @@ func TestContextHierarchyAndFork(t *testing.T) {
 
 	// Child provides LogService
 	childLog := &logServiceImpl{}
-	core.Provide[LogService](child, childLog)
+	core.ProvideScoped[LogService](child, childLog)
 
 	// Child has LogService, parent does not
 	assert.True(t, core.Has[LogService](child))
 	assert.False(t, core.Has[LogService](parent))
 
-	// Child overrides SampleService
-	core.Provide[SampleService](child, &sampleServiceImpl{prefix: "Child:"})
+	// Child overrides SampleService locally
+	core.ProvideScoped[SampleService](child, &sampleServiceImpl{prefix: "Child:"})
 	childSvc, err := core.Inject[SampleService](child)
 	require.NoError(t, err)
 	assert.Equal(t, "Child: Ryan", childSvc.Greet("Ryan"))

backend/core/fiber.go

@@ -0,0 +1,157 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package core
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+)
+
+// FiberState represents the lifecycle status of a plugin instance in the Cordis micro-kernel.
+type FiberState string
+
+const (
+	// FiberPending indicates the plugin is waiting for its required dependencies to be provided.
+	FiberPending FiberState = "PENDING"
+
+	// FiberLoading indicates the plugin is currently running its Apply mounting phase.
+	FiberLoading FiberState = "LOADING"
+
+	// FiberActive indicates the plugin is fully mounted, active, and operating without error.
+	FiberActive FiberState = "ACTIVE"
+
+	// FiberUnloading indicates the plugin is tearing down its scoped effects in LIFO order.
+	FiberUnloading FiberState = "UNLOADING"
+
+	// FiberDisposed indicates the plugin has been completely unmounted and its context disposed.
+	FiberDisposed FiberState = "DISPOSED"
+)
+
+// Fiber wraps a Plugin instance with a dedicated scoped Context and manages its
+// reactive lifecycle state machine according to Cordis spatiotemporal composability principles.
+type Fiber struct {
+	mu     sync.RWMutex
+	plugin Plugin
+	state  FiberState
+	ctx    *Context
+	deps   []reflect.Type
+	err    error
+}
+
+// NewFiber creates a new Fiber for the specified plugin with a child scoped context.
+func NewFiber(rootCtx *Context, plugin Plugin) *Fiber {
+	var deps []reflect.Type
+	if depPlugin, ok := plugin.(DependentPlugin); ok {
+		deps = depPlugin.Inject()
+	}
+
+	return &Fiber{
+		plugin: plugin,
+		state:  FiberPending,
+		ctx:    rootCtx.Fork(),
+		deps:   deps,
+	}
+}
+
+// Plugin returns the underlying Plugin instance.
+func (f *Fiber) Plugin() Plugin {
+	return f.plugin
+}
+
+// Name returns the unique identifier of the plugin.
+func (f *Fiber) Name() string {
+	if f.plugin == nil {
+		return ""
+	}
+	return f.plugin.Name()
+}
+
+// State returns the current lifecycle state of this Fiber.
+func (f *Fiber) State() FiberState {
+	f.mu.RLock()
+	defer f.mu.RUnlock()
+	return f.state
+}
+
+// Context returns the dedicated scoped Context for this Fiber.
+func (f *Fiber) Context() *Context {
+	return f.ctx
+}
+
+// Dependencies returns the list of required service reflect.Types.
+func (f *Fiber) Dependencies() []reflect.Type {
+	res := make([]reflect.Type, len(f.deps))
+	copy(res, f.deps)
+	return res
+}
+
+// Error returns the latest mounting or unmounting error, if any.
+func (f *Fiber) Error() error {
+	f.mu.RLock()
+	defer f.mu.RUnlock()
+	return f.err
+}
+
+// DependenciesSatisfied checks if all declared dependencies are present in the target Context container.
+func (f *Fiber) DependenciesSatisfied(ctx *Context) bool {
+	if len(f.deps) == 0 {
+		return true
+	}
+	container := ctx.Container()
+	for _, dep := range f.deps {
+		if _, err := container.resolve(dep); err != nil {
+			return false
+		}
+	}
+	return true
+}
+
+// Load executes the plugin mounting lifecycle: PENDING -> LOADING -> ACTIVE.
+func (f *Fiber) Load() error {
+	f.mu.Lock()
+	if f.state != FiberPending {
+		f.mu.Unlock()
+		return nil
+	}
+	f.state = FiberLoading
+	f.err = nil
+	f.mu.Unlock()
+
+	if err := f.plugin.Apply(f.ctx); err != nil {
+		f.mu.Lock()
+		f.err = fmt.Errorf("fiber %q: apply failed: %w", f.Name(), err)
+		f.state = FiberPending
+		_ = f.ctx.Dispose()
+		f.mu.Unlock()
+		return err
+	}
+
+	f.mu.Lock()
+	f.state = FiberActive
+	f.mu.Unlock()
+	return nil
+}
+
+// Unload tears down the plugin: ACTIVE -> UNLOADING -> DISPOSED.
+func (f *Fiber) Unload() error {
+	f.mu.Lock()
+	if f.state != FiberActive && f.state != FiberLoading {
+		f.mu.Unlock()
+		return nil
+	}
+	f.state = FiberUnloading
+	f.mu.Unlock()
+
+	err := f.ctx.Dispose()
+
+	f.mu.Lock()
+	f.state = FiberDisposed
+	if err != nil {
+		f.err = err
+	}
+	f.mu.Unlock()
+
+	return err
+}

backend/core/fiber_test.go

@@ -0,0 +1,111 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package core_test
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"Wavelet/core"
+)
+
+type MockServiceA interface {
+	DoA() string
+}
+
+type mockServiceAImpl struct{}
+
+func (m *mockServiceAImpl) DoA() string { return "doneA" }
+
+type MockServiceB interface {
+	DoB() string
+}
+
+type mockServiceBImpl struct{}
+
+func (m *mockServiceBImpl) DoB() string { return "doneB" }
+
+type mockProviderPlugin struct {
+	name    string
+	applied bool
+}
+
+func (p *mockProviderPlugin) Name() string {
+	return p.name
+}
+
+func (p *mockProviderPlugin) Apply(ctx *core.Context) error {
+	p.applied = true
+	core.Provide[MockServiceA](ctx, &mockServiceAImpl{})
+	return nil
+}
+
+type mockConsumerPlugin struct {
+	name    string
+	applied bool
+	gotSvc  MockServiceA
+}
+
+func (p *mockConsumerPlugin) Name() string {
+	return p.name
+}
+
+func (p *mockConsumerPlugin) Inject() []reflect.Type {
+	return []reflect.Type{
+		reflect.TypeFor[MockServiceA](),
+	}
+}
+
+func (p *mockConsumerPlugin) Apply(ctx *core.Context) error {
+	p.applied = true
+	svc, err := core.Inject[MockServiceA](ctx)
+	if err != nil {
+		return err
+	}
+	p.gotSvc = svc
+	return nil
+}
+
+func TestFiber_ConfluenceAndReactiveActivation(t *testing.T) {
+	app := core.NewApp()
+
+	// Register Consumer BEFORE Provider to test confluence & out-of-order dependency resolution
+	consumer := &mockConsumerPlugin{name: "consumer-plugin"}
+	provider := &mockProviderPlugin{name: "provider-plugin"}
+
+	app.Use(consumer, provider)
+
+	err := app.Start(context.Background())
+	require.NoError(t, err)
+
+	assert.True(t, provider.applied, "provider should be applied")
+	assert.True(t, consumer.applied, "consumer should be reactively applied once dependency was provided")
+	assert.NotNil(t, consumer.gotSvc)
+	assert.Equal(t, "doneA", consumer.gotSvc.DoA())
+
+	fibers := app.Fibers()
+	require.Equal(t, 2, len(fibers))
+	for _, f := range fibers {
+		assert.Equal(t, core.FiberActive, f.State())
+	}
+
+	err = app.Stop()
+	assert.NoError(t, err)
+}
+
+func TestFiber_UnsatisfiedDependencyReturnsError(t *testing.T) {
+	app := core.NewApp()
+
+	// Register Consumer whose dependency is never provided
+	consumer := &mockConsumerPlugin{name: "consumer-plugin"}
+	app.Use(consumer)
+
+	err := app.Start(context.Background())
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "unsatisfied dependencies")
+}

backend/core/types.go

@@ -6,6 +6,7 @@ package core
 import (
 	"context"
 	"errors"
+	"reflect"
 
 	"Wavelet/core/extpoints"
 )
@@ -48,6 +49,12 @@ type Plugin interface {
 	Apply(ctx *Context) error
 }
 
+// DependentPlugin is an optional extension interface for plugins that declare required service dependencies.
+type DependentPlugin interface {
+	Plugin
+	Inject() []reflect.Type
+}
+
 // PluginWithManifest is an optional extension interface for plugins that declare metadata.
 type PluginWithManifest interface {
 	Plugin