feat(FN-1216): rename extension tools to fn_* across CLI and docs

- Rename all pi extension tool registrations from kb_* to fn_* across task, mission, and agent tool families
- Update extension and skill-sync tests plus Fusion skill docs/workflows to assert and document the new fn_* tool names
- Align product-identity strings across core, dashboard, and CLI references, including GitHub import examples, User-Agent headers, and terminal TERM_PROGRAM
- Add a @gsxdsm/fusion minor changeset describing the extension tool-prefix rename

packages/core/src/agent-prompts.ts

@@ -21,7 +21,7 @@ import type { AgentCapability, AgentPromptTemplate, AgentPromptsConfig } from ".
 // Built-in prompt text (derived from engine constants — keep in sync)
 // ---------------------------------------------------------------------------
 
-const EXECUTOR_PROMPT_TEXT = `You are a task execution agent for "kb", an AI-orchestrated task board.
+const EXECUTOR_PROMPT_TEXT = `You are a task execution agent for "fn", an AI-orchestrated task board.
 
 You are working in a git worktree isolated from the main branch. Your job is to implement the task described in the PROMPT.md specification you're given.
 
@@ -143,7 +143,7 @@ Tests and typecheck are also hard quality gates:
 - If the repository exposes a typecheck command, run it and keep fixing failures until it passes
 - Do not stop at "out of scope" if additional fixes are required to restore green tests, build, or typecheck`;
 
-const TRIAGE_PROMPT_TEXT = `You are a task specification agent for "kb", an AI-orchestrated task board.
+const TRIAGE_PROMPT_TEXT = `You are a task specification agent for "fn", an AI-orchestrated task board.
 
 Your job: take a rough task description and produce a fully specified PROMPT.md that another AI agent can execute autonomously in a fresh context with zero memory of this conversation.
 
@@ -372,7 +372,7 @@ access to the codebase and can run commands to inspect code.
  * appended dynamically by the merger's buildMergeSystemPrompt function).
  * Derived from the merger's hardcoded prompt — keep in sync.
  */
-const MERGER_BASE_PROMPT_TEXT = `You are a merge agent for "kb", an AI-orchestrated task board.
+const MERGER_BASE_PROMPT_TEXT = `You are a merge agent for "fn", an AI-orchestrated task board.
 
 Your job is to finalize a squash merge: resolve any conflicts and write a good commit message.
 All changes from the branch are squashed into a single commit.
@@ -390,7 +390,7 @@ If there are merge conflicts:
 // Additional role variant prompt texts
 // ---------------------------------------------------------------------------
 
-const SENIOR_ENGINEER_PROMPT_TEXT = `You are a senior engineering agent for "kb", an AI-orchestrated task board.
+const SENIOR_ENGINEER_PROMPT_TEXT = `You are a senior engineering agent for "fn", an AI-orchestrated task board.
 
 You are working in a git worktree isolated from the main branch. Your job is to implement the task described in the PROMPT.md specification you're given. You operate with a high degree of autonomy, making architectural decisions and balancing trade-offs independently.
 
@@ -614,7 +614,7 @@ submissions to a high bar for correctness, security, and maintainability.
 - [Optional improvements, not blocking]
 \`\`\``;
 
-const CONCISE_TRIAGE_PROMPT_TEXT = `You are a task specification agent for "kb". Produce a concise, actionable PROMPT.md from the given task description.
+const CONCISE_TRIAGE_PROMPT_TEXT = `You are a task specification agent for "fn". Produce a concise, actionable PROMPT.md from the given task description.
 
 ## What you produce
 Write a PROMPT.md specification to the given path. Be brief and precise — avoid verbosity.

packages/core/src/agent-store.ts

@@ -76,7 +76,7 @@ type TypedEventEmitter<Events extends Record<string, unknown[]>> = {
 
 /** Options for AgentStore constructor */
 export interface AgentStoreOptions {
-  /** Root directory for kb data (default: .fusion) */
+  /** Root directory for fn data (default: .fusion) */
   rootDir?: string;
 }
 

packages/core/src/central-core.ts

@@ -1,5 +1,5 @@
 /**
- * CentralCore — Main API for kb's multi-project central infrastructure.
+ * CentralCore — Main API for fn's multi-project central infrastructure.
  *
  * Provides project registry, health tracking, unified activity feed,
  * and global concurrency management across all registered projects.
@@ -1560,7 +1560,7 @@ export class CentralCore extends EventEmitter<CentralCoreEvents> {
   /**
    * Get the global directory path.
    *
-   * @returns Absolute path to global kb directory
+   * @returns Absolute path to global fn directory
    */
   getGlobalDir(): string {
     return this.globalDir;

packages/core/src/central-db.ts

@@ -1,5 +1,5 @@
 /**
- * Central SQLite database module for kb's multi-project architecture.
+ * Central SQLite database module for fn's multi-project architecture.
  *
  * Uses Node.js built-in `node:sqlite` (DatabaseSync) for simplified
  * synchronous transaction handling. The database runs in WAL mode

packages/core/src/db-migrate.ts

@@ -39,7 +39,7 @@ export function detectLegacyData(kbDir: string): boolean {
 }
 
 /**
- * Get the migration status of a kb directory.
+ * Get the migration status of a fn directory.
  */
 export function getMigrationStatus(kbDir: string): {
   hasLegacy: boolean;

packages/core/src/db.ts

@@ -1,5 +1,5 @@
 /**
- * SQLite database module for kb task board storage.
+ * SQLite database module for fn task board storage.
  *
  * Uses Node.js built-in `node:sqlite` (DatabaseSync) for simplified
  * synchronous transaction handling. The database runs in WAL mode

packages/core/src/first-run.ts

@@ -3,7 +3,7 @@
  *
  * Handles the transition from single-project to multi-project mode:
  * - Detects if this is a fresh installation (no projects registered)
- * - Auto-detects existing kb projects from current working directory
+ * - Auto-detects existing fn projects from current working directory
  * - Guides users through initial project registration
  * - Provides setup state for dashboard wizard UI
  *
@@ -87,7 +87,7 @@ export class FirstRunExperience {
    * Detect or create the initial project.
    *
    * Tries the following in order:
-   * 1. Detect existing kb project from `process.cwd()`
+   * 1. Detect existing fn project from `process.cwd()`
    * 2. If found, auto-register it and return
    * 3. If not found, return guidance for manual setup
    *

packages/core/src/global-settings.ts

@@ -1,7 +1,7 @@
 /**
  * Global settings store — manages user-level settings in `~/.pi/fusion/settings.json`.
  *
- * Global settings persist across all kb projects for the current user.
+ * Global settings persist across all fn projects for the current user.
  * They include UI theme preferences, default AI model selection, and
  * notification configuration.
  *
@@ -34,7 +34,7 @@ export function defaultGlobalDir(): string {
  * Resolve the active global directory.
  *
  * If the new `~/.pi/fusion` directory does not exist but the legacy
- * `~/.pi/kb` directory does, move the legacy directory into place so
+ * `~/.pi/fusion` directory does, move the legacy directory into place so
  * existing settings and central metadata continue to work after upgrade.
  */
 export function resolveGlobalDir(dir?: string): string {

packages/core/src/message-store.ts

@@ -37,7 +37,7 @@ export interface MessageStoreEvents {
 
 /** Options for MessageStore constructor */
 export interface MessageStoreOptions {
-  /** Root directory for kb data (default: .fusion) */
+  /** Root directory for fn data (default: .fusion) */
   rootDir?: string;
   /** Optional hook invoked when a message is addressed to an agent */
   onMessageToAgent?: (message: Message) => void;

packages/core/src/mission-store.ts

@@ -1337,7 +1337,7 @@ export class MissionStore extends EventEmitter<MissionStoreEvents> {
   /**
    * Triage a feature by creating a new task and linking it.
    *
-   * Creates a kb task from the feature's title and description, then links
+   * Creates a fn task from the feature's title and description, then links
    * the feature to the newly created task using `linkFeatureToTask()`.
    * The feature status transitions from "defined" to "triaged".
    *

packages/core/src/mission-types.ts

@@ -1,10 +1,10 @@
 /**
- * Mission hierarchy types for kb project planning.
+ * Mission hierarchy types for fn project planning.
  *
  * A Mission represents a high-level objective that can span multiple milestones.
  * Each Milestone represents a phase of work within a mission.
  * Each Slice represents a work unit within a milestone that can be activated for implementation.
- * Each Feature represents a deliverable within a slice that can be linked to a kb Task.
+ * Each Feature represents a deliverable within a slice that can be linked to a fn Task.
  *
  * The hierarchy: Mission → Milestone → Slice → Feature → (optional) Task
  */
@@ -153,7 +153,7 @@ export interface Milestone {
 
 /**
  * A Slice represents a work unit within a milestone.
- * Slices can be activated for implementation, linking to kb tasks.
+ * Slices can be activated for implementation, linking to fn tasks.
  */
 export interface Slice {
   /** Unique identifier (e.g., "SL-P4T2WX-D5E8") */
@@ -178,7 +178,7 @@ export interface Slice {
 
 /**
  * A MissionFeature represents a deliverable within a slice.
- * Features can be linked to kb Tasks for implementation.
+ * Features can be linked to fn Tasks for implementation.
  */
 export interface MissionFeature {
   /** Unique identifier (e.g., "F-J6K9AB-G7H3") */

packages/core/src/reflection-store.ts

@@ -20,7 +20,7 @@ export interface ReflectionStoreEvents {
 
 /** Constructor options for ReflectionStore. */
 export interface ReflectionStoreOptions {
-  /** Root kb data directory (default: .fusion). */
+  /** Root fn data directory (default: .fusion). */
   rootDir?: string;
 }
 

packages/core/src/settings-export.ts

@@ -1,7 +1,7 @@
 /**
  * Settings export and import functionality.
  *
- * This module provides utilities for exporting and importing kb settings,
+ * This module provides utilities for exporting and importing fn settings,
  * supporting both global (~/.pi/fusion/settings.json) and project-level (.fusion/config.json)
  * settings for backup, migration, and sharing.
  */

packages/core/src/types.ts

@@ -566,8 +566,8 @@ export interface Task {
    *  dependency's branch instead of HEAD. Cleared after worktree creation. */
   baseBranch?: string;
   /** Actual git branch name used for this task's worktree. May differ from
-   *  the conventional `kb/{task-id}` when conflict recovery generated a
-   *  unique suffixed name (e.g., `kb/fn-042-2`). The merger and PR systems
+   *  the conventional `fn/{task-id}` when conflict recovery generated a
+   *  unique suffixed name (e.g., `fn/fn-042-2`). The merger and PR systems
    *  read this field instead of deriving the branch from the task ID. */
   branch?: string;
   /** Base commit SHA for creating this task's worktree. Used with baseBranch
@@ -709,7 +709,7 @@ export interface TaskCreateInput {
 // Settings are split into two scopes:
 //
 // 1. **GlobalSettings** — User preferences stored in `~/.pi/fusion/settings.json`.
-//    These persist across all kb projects for the current user (theme, default
+//    These persist across all fn projects for the current user (theme, default
 //    AI models, notification preferences).
 //
 // 2. **ProjectSettings** — Project-specific workflow and resource settings stored
@@ -729,7 +729,7 @@ export type SettingsScope = "global" | "project";
 /**
  * Global (user-level) settings stored in `~/.pi/fusion/settings.json`.
  *
- * These are user preferences that persist across all kb projects.
+ * These are user preferences that persist across all fn projects.
  * The dashboard UI shows these under a "Global" section.
  */
 export interface GlobalSettings {
@@ -777,7 +777,7 @@ export interface GlobalSettings {
   ntfyDashboardHost?: string;
   /** The default project ID for CLI operations when --project flag is not provided.
    *  Used to determine which project to operate on when not in a project directory.
-   *  Set via `kb project set-default <name>`. */
+   *  Set via `fn project set-default <name>`. */
   defaultProjectId?: string;
   /** Whether the first-run setup wizard has been completed.
    *  Set to true when the user completes the multi-project setup process.
@@ -854,7 +854,7 @@ export interface ProjectSettings {
   /** Controls how worktree directory names are generated when creating fresh worktrees.
    *  Only applies when recycleWorktrees is NOT enabled (pooled worktrees retain their existing names).
    *  - "random": Human-friendly adjective-noun names (e.g., swift-falcon) — default
-   *  - "task-id": Use the task ID (e.g., kb-042)
+   *  - "task-id": Use the task ID (e.g., fn-042)
    *  - "task-title": Use a slugified version of the task title (e.g., fix-login-bug)
    *  Default: "random". */
   worktreeNaming?: "random" | "task-id" | "task-title";