feat(skills): Implement report generation skill (Phase 6)

[arjun-zosma]

Description

Implement the report generation skill at packages/skills/reports/ (currently an empty placeholder: export {}). This skill enables agents to produce formatted deliverables -- PDF reports, PPTX presentations, charts, and data exports.

Two approaches are supported simultaneously:

A) Template-based reports

Agent produces structured JSON matching a predefined template schema. The skill renders it into the requested format.

• Implement report_list_templates tool: returns available templates with their JSON schemas
• Implement report_generate tool: accepts template name + format + structured data, produces output file
• Rendering stack:
  • PDF: React-PDF (@react-pdf/renderer)
  • PPTX: pptxgenjs
  • Charts: chart.js with chartjs-node-canvas (server-side PNG/SVG rendering)
• Built-in template: MonthlyReportData with title, period, summary metrics, charts (bar/line/pie), and tables
• Template schema validation before rendering (fail fast with clear error messages)

B) Agent-generated code reports

Agent writes Python or JavaScript code that runs inside the sandbox to produce visualizations and reports.

• Implement report_execute_code tool: accepts language, code, optional dependencies
• Execution flow:
  1. Install dependencies (pip install / npm install) if specified
  2. Write code to temp file
  3. Execute with 60-second timeout
  4. Glob /workspace/output/*.{png,svg,pdf,pptx,csv,xlsx} for output files
• Pre-installed Python libraries in sandbox image: matplotlib, pandas, numpy, seaborn
• Available JS libraries: chart.js + chartjs-node-canvas, d3

Output format matrix

Format	Template approach	Code approach
PDF	React-PDF	matplotlib / reportlab
PPTX	pptxgenjs	python-pptx
PNG	chart.js canvas	matplotlib / chart.js
SVG	chart.js canvas	matplotlib / D3
CSV	built-in	pandas
XLSX	exceljs	openpyxl

File delivery

• Files saved to /workspace/output/ in sandbox
• Orchestrator copies files out via sandbox file API
• Upload to temporary storage (S3-compatible or local filesystem)
• Return download URLs to the client
• Channel-specific delivery:
  • Web: download link in chat message
  • Slack: file upload to thread via files.upload
  • WhatsApp: media message

Sandbox Dockerfile updates

• Install Python report dependencies: matplotlib, pandas, numpy, seaborn, reportlab, python-pptx, openpyxl

• Install Node report dependencies: @react-pdf/renderer, pptxgenjs, chart.js, chartjs-node-canvas, exceljs, d3

• Create /workspace/output/ directory with sandbox user write permissions

• skills/reports

• orchestrator

• sandbox

Motivation

Agents need to produce deliverables beyond text -- PDF reports, presentations, charts, data exports. This is essential for enterprise use cases: monthly performance reports, data analysis summaries, executive presentations, financial exports. The report skill makes agents productive for knowledge work that requires formatted, shareable output.

Affected package(s)

skills/reports, orchestrator, sandbox

Alternatives considered

• Code-only approach (no templates) -- less consistent output quality; templates guarantee a professional baseline.
• Third-party report generation service -- adds external dependency, latency, and cost; in-sandbox generation is self-contained.
• Markdown-only output -- insufficient for enterprise needs; stakeholders expect PDF/PPTX.