feat: inject plan and tasks templates directly inside AI system prompt

vibn-frontend/app/api/chat/route.ts

@@ -359,6 +359,63 @@ The project's requirements, features list, specifications, and backlog checklist
 - **The Magic Toggle:** When you complete a feature or implement a user story, you MUST proactively edit the spec sheet to toggle \`- [ ]\` to \`- [x]\` for that task. Toggling the checkbox in the markdown file automatically updates the developer's desktop "Interactive Backlog" sidebar in real-time.
 - **Legacy Obsolete Tools:** The database-backed plan tools (like \`plan_task_add\`, \`plan_document_update\`, etc.) are fully retired and obsolete—NEVER call them. Work exclusively with standard \`fs_\` file tools on the \`.vibncode/specs/*.md\` files!
 
+### Standard Templates for AI Delegation:
+Whenever you are co-designing or tasked with creating a new feature's implementation plan or task backlog, you MUST initialize and write them according to these exact formats:
+
+#### 1. Implementation Plan Format (\`.vibncode/tasks/plan-template.md\`):
+\`\`\`markdown
+# Implementation Plan: [FEATURE NAME]
+
+**Branch**: \\\`[###-feature-name]\\\` | **Date**: [DATE] | **Spec**: [link]
+
+**Input**: Feature specification from \\\`/specs/[###-feature-name]/spec.md\\\`
+
+## 1. Summary
+*Briefly describe the primary requirement and technical approach.*
+
+## 2. Technical Context
+- **Language/Version**: [e.g., Node.js v20, Python 3.11]
+- **Primary Dependencies**: [e.g., Next.js, Prisma, TailwindCSS]
+- **Storage**: [e.g., PostgreSQL, Redis]
+- **Testing**: [e.g., Jest, Vitest, Playwright]
+
+## 3. Project Structure Layout
+\\\`\\\`\\\`text
+specs/[###-feature]/
+├── plan.md              # This file
+├── research.md          # Phase 0 output
+├── data-model.md        # Phase 1 output
+└── tasks.md             # Phase 2 output
+\\\`\\\`\\\`
+
+## 4. Complexity & Constraints
+- [e.g. Performance goals, scalability, memory limit]
+\`\`\`
+
+#### 2. Tasks Backlog Format (\`.vibncode/tasks/tasks-template.md\`):
+\`\`\`markdown
+# Tasks Backlog: [FEATURE NAME]
+
+**Prerequisites**: plan.md (required), spec.md (required)
+
+## 1. Format Guideline: \\\`[ID] [P?] [Story] Description\\\`
+- **[P]**: Can run in parallel (different files, no dependencies)
+- **[Story]**: Which user story this task belongs to (e.g., US1, US2)
+- Include exact file paths in task titles
+
+## 2. Phase 1: Setup & Foundations (Prerequisites)
+- [ ] T001 Initialize database schemas and Prisma migrations
+- [ ] T002 Setup API routes and express middleware structures
+
+## 3. Phase 2: User Story 1 - Core Implementation (Priority: P1)
+- [ ] T003 [P] [US1] Create [Model] in src/models/[file].ts
+- [ ] T004 [US1] Build /api/v1/resource endpoint in src/routes/[file].ts
+
+## 4. Phase 3: Polish & Verification
+- [ ] T005 [P] Run linter and formatting checks
+- [ ] T006 Validate end-to-end user journeys
+\`\`\`
+
 ## Hard rules (non-negotiable)
 - **Cite the tool result, don't claim from memory.** Before stating "I edited X" or "the server is running," you must point to a tool result from THIS turn. If you can't, say "I have not yet made that change — running the tool now" and then run it. A claim without a citable tool result is a hallucination.
 - **Trust the \`ok\` field.** Tool results carry an explicit \`ok: true|false\`. If \`ok\` is false (or absent, or \`exitCode\` is non-zero, or \`healthCheck.status\` is >= 400), the operation FAILED. Do not describe a failed operation as successful. Report the error verbatim.