feat(FN-3309): remove PI install references and documentation

Merges the final step for FN-3309, adding a changeset to document the removal of pi install references. The changeset is the only file changed, completing the feature work.

Fusion-Task-Id: FN-3309

packages/cli/skill/fusion/SKILL.md

@@ -19,11 +19,11 @@ Fusion is an AI-orchestrated task board. You throw in rough ideas; AI specifies,
 **Missions** provide hierarchical planning above tasks:
 Mission → Milestone → Slice → Feature → Task
 
-**Available tools:** Fusion registers tools via the pi extension (prefixed `fn_*`). No CLI commands or Bash needed — use the registered tools directly.
+**Available tools:** Fusion registers tools (prefixed `fn_*`). No CLI commands or Bash needed — use the registered tools directly.
 
-**Naming boundary:** The published pi-extension skill surface uses `fn_*` tool names (for example `fn_task_create`, `fn_mission_create`). Engine runtime sessions also inject additional `fn_*` tools (for example `fn_review_spec`, `fn_review_step`, `fn_spawn_agent`) that are not user-invokable extension tools.
+**Naming boundary:** The published skill surface uses `fn_*` tool names (for example `fn_task_create`, `fn_mission_create`). Engine runtime sessions also inject additional `fn_*` tools (for example `fn_review_spec`, `fn_review_step`, `fn_spawn_agent`) that are not part of the published skill surface.
 
-**Engine runtime tools:** Triage/executor/merger/heartbeat sessions include auto-injected engine tools that do not come from the pi extension registration list. See `references/engine-tools.md` for the canonical runtime-only catalog and usage boundaries.
+**Engine runtime tools:** Triage/executor/merger/heartbeat sessions include auto-injected engine tools that are not part of the published skill surface. See `references/engine-tools.md` for the canonical runtime-only catalog and usage boundaries.
 
 **Tool categories:**
 <!-- BEGIN: tool-categories (auto-generated by scripts/sync-fusion-skill-tools.mjs — do not edit by hand) -->
@@ -85,7 +85,7 @@ Use `fn_mission_create` for high-level objectives, then add milestones, slices,
 
 <known_limitations>
 
-These operations are **not available** via pi extension tools and require the dashboard or CLI:
+These operations are **not available** via extension tools and require the dashboard or CLI:
 
 - **Moving tasks between columns** — No tool for column moves (handled by the AI engine)
 - **Workflow steps** — Creating/managing workflow step definitions requires the dashboard
@@ -103,7 +103,7 @@ For these operations, guide the user to the dashboard (`/fn`) or CLI commands do
 |-----------|-------------|
 | references/cli-commands.md | Full CLI command reference |
 | references/task-structure.md | Task file structure and storage |
-| references/extension-tools.md | All pi extension tools with parameters |
+| references/extension-tools.md | All extension tools with parameters |
 | references/best-practices.md | Tips for effective Fusion usage |
 | references/fusion-capabilities.md | Complete feature catalog |
 | references/engine-tools.md | Engine session-scoped runtime tools (not extension-invokable) |

packages/cli/skill/fusion/references/engine-tools.md

@@ -1,10 +1,10 @@
 # Engine Session-Scoped Tools
 
-These tools are **not** part of the pi extension's user-invokable `extension.ts` surface. They are injected by the engine at runtime for specific agent session types.
+These tools are **not** part of the user-invokable extension surface. They are injected by the engine at runtime for specific agent session types.
 
 - Source files: `packages/engine/src/agent-tools.ts`, `triage.ts`, `executor.ts`, `merger.ts`, `agent-heartbeat.ts`
 - Availability: only when the engine creates a session for the matching agent role
-- Important: do not tell users to call these directly from the generic pi extension tool list
+- Important: do not tell users to call these directly from the generic extension tool list
 
 ## Shared runtime tools (`agent-tools.ts`)
 

packages/cli/skill/fusion/references/extension-tools.md

@@ -1,6 +1,6 @@
-# Fusion Pi Extension Tools
+# Fusion Extension Tools
 
-All tools are registered via the pi extension. They are available in any pi agent session when the Fusion extension is installed.
+All tools are registered via the Fusion extension. They are available in any agent session when Fusion is configured.
 
 > Naming contract: all externally exposed Fusion extension tools are `fn_*` (for example `fn_task_create`). Engine runtime sessions also inject additional `fn_*` tools (for example `fn_review_step`, `fn_spawn_agent`, `fn_task_document_write`) that are separate from this extension surface and documented in `engine-tools.md`.
 
@@ -364,7 +364,7 @@ Cancel a research run.
 
 ### /fn
 
-Start or stop the Fusion dashboard from within a pi session.
+Start or stop the Fusion dashboard from within an agent session.
 
 | Command | Description |
 |---------|-------------|

packages/cli/skill/fusion/references/fusion-capabilities.md

@@ -5,7 +5,7 @@
 Fusion is an AI-orchestrated task board. Tasks flow through columns:
 Triage → Todo → In Progress → In Review → Done → Archived
 
-## Pi Extension Tools (Available to Agents)
+## Extension Tools (Available to Agents)
 
 All skill/extension tool invocations in this catalog use the public `fn_*` namespace. Engine runtime sessions also have additional runtime-only `fn_*` tools that are intentionally not listed here (see `references/engine-tools.md`).
 

packages/cli/skill/fusion/references/skill-patterns.md

@@ -30,7 +30,7 @@
 ## Key Takeaways for Fusion Skill
 
 1. **Use router pattern** — Fusion has multiple distinct workflows (task management, lifecycle, specs, dashboard/CLI)
-2. **No `allowed-tools` needed** — Fusion tools are registered via pi extension, not Bash CLI
+2. **No `allowed-tools` needed** — Fusion tools are registered via the extension, not Bash CLI
 3. **Inline essential concepts** — Task columns, workflow overview in SKILL.md
 4. **Progressive disclosure** — SKILL.md routes to workflows, workflows reference detailed docs
 5. **Pure XML structure** — No markdown headings (#, ##, ###) in body

packages/cli/skill/fusion/workflows/dashboard-cli.md

@@ -3,14 +3,14 @@
 </required_reading>
 
 <objective>
-Guide the agent through using the Fusion dashboard and CLI for operations not available via pi extension tools.
+Guide the agent through using the Fusion dashboard and CLI for operations not available via extension tools.
 </objective>
 
 <process>
 
 **Starting the dashboard:**
 
-Use the `/fn` command (registered by the pi extension):
+Use the `/fn` command (registered by the Fusion extension):
 - `/fn` or `/fn 4040` — Start dashboard + AI engine on specified port (default 4040)
 - `/fn stop` — Stop the dashboard
 - `/fn status` — Check if dashboard is running
@@ -28,7 +28,7 @@ The dashboard provides:
 
 **Operations that require CLI or dashboard:**
 
-These cannot be done with pi extension tools:
+These cannot be done with extension tools:
 
 | Operation | CLI Command | Dashboard |
 |-----------|-------------|-----------|

packages/cli/skill/fusion/workflows/task-management.md

@@ -4,7 +4,7 @@
 </required_reading>
 
 <objective>
-Guide the agent through creating, viewing, and managing tasks on the Fusion board using pi extension tools.
+Guide the agent through creating, viewing, and managing tasks on the Fusion board using extension tools.
 
 Use only the public `fn_*` extension tools in this workflow. Do not substitute internal engine runtime tools like `task_create`, `task_update`, `task_log`, or `task_done`.
 </objective>