feat: gated project experience & prompt intelligence

Implements the full gated session flow and prompt intelligence system:

- Prisma schema: add gated, priority, summary, chapters, linkTarget fields
- Session gate: state machine (gated → begin_session → ungated) with LLM-powered
  tool selection based on prompt index
- Tag matcher: intelligent prompt-to-tool matching with project/server/action tags
- LLM selector: tiered provider selection (fast for gating, heavy for complex tasks)
- Link resolver: cross-project MCP resource references (project/server:uri format)
- Prompt summary service: LLM-generated summaries and chapter extraction
- System project bootstrap: ensures default project exists on startup
- Structural link health checks: enrichWithLinkStatus on prompt GET endpoints
- CLI: create prompt --priority/--link, create project --gated/--no-gated,
  describe project shows prompts section, get prompts shows PRI/LINK/STATUS
- Apply/edit: priority, linkTarget, gated fields supported
- Shell completions: fish updated with new flags
- 1,253 tests passing across all packages

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/db/prisma/migrations/20260225220000_add_gated_prompt_priority_summary_link/migration.sql

@@ -0,0 +1,11 @@
+-- AlterTable: Add gated flag to Project
+ALTER TABLE "Project" ADD COLUMN "gated" BOOLEAN NOT NULL DEFAULT true;
+
+-- AlterTable: Add priority, summary, chapters, linkTarget to Prompt
+ALTER TABLE "Prompt" ADD COLUMN "priority" INTEGER NOT NULL DEFAULT 5;
+ALTER TABLE "Prompt" ADD COLUMN "summary" TEXT;
+ALTER TABLE "Prompt" ADD COLUMN "chapters" JSONB;
+ALTER TABLE "Prompt" ADD COLUMN "linkTarget" TEXT;
+
+-- AlterTable: Add priority to PromptRequest
+ALTER TABLE "PromptRequest" ADD COLUMN "priority" INTEGER NOT NULL DEFAULT 5;

src/db/prisma/schema.prisma

@@ -172,6 +172,7 @@ model Project {
   description String   @default("")
   prompt      String   @default("")
   proxyMode   String   @default("direct")
+  gated       Boolean  @default(true)
   llmProvider String?
   llmModel    String?
   ownerId     String
@@ -233,13 +234,17 @@ enum InstanceStatus {
 // ── Prompts (approved content resources) ──
 
 model Prompt {
-  id        String   @id @default(cuid())
-  name      String
-  content   String   @db.Text
-  projectId String?
-  version   Int      @default(1)
-  createdAt DateTime @default(now())
-  updatedAt DateTime @updatedAt
+  id         String   @id @default(cuid())
+  name       String
+  content    String   @db.Text
+  projectId  String?
+  priority   Int      @default(5)
+  summary    String?  @db.Text
+  chapters   Json?
+  linkTarget String?
+  version    Int      @default(1)
+  createdAt  DateTime @default(now())
+  updatedAt  DateTime @updatedAt
 
   project Project? @relation(fields: [projectId], references: [id], onDelete: Cascade)
 
@@ -254,6 +259,7 @@ model PromptRequest {
   name             String
   content          String   @db.Text
   projectId        String?
+  priority         Int      @default(5)
   createdBySession String?
   createdByUserId  String?
   createdAt        DateTime @default(now())