feat(pi): add Pi and Oh My Pi support

[timseriakov]

Summary

Adds first-class Pi and Oh My Pi support to Codbash.

Pi and Oh My Pi (Fork of Pi) sessions now show up in the dashboard alongside the existing agents, can be searched, previewed, opened in detail, resumed from the UI/CLI, included in analytics, and shown separately in leaderboard stats.

Companion PR

• Public leaderboard badge colors: feat: add Pi and Oh My Pi badge colors codedash-leaderboard#1

What's new

Surface	Change
Agent detection	Detects Pi via pi and Oh My Pi via omp, with Settings detection metadata and tests.
Session loading	Reads Pi / Oh My Pi JSONL sessions from their agent directories, including canonical nested session layouts.
Session detail	Parses messages, timestamps, projects, models, token usage, and cost metadata into the existing session/detail UI shape.
Resume / launch	Generates shell-safe Pi / Oh My Pi resume commands and launches terminal resumes through the existing /api/launch flow.
Sidebar	Adds separate Pi and Oh My Pi filters in the Agents section and Sidebar settings.
Analytics	Includes Pi / Oh My Pi sessions in cost and usage analytics using real usage/cost data when present.
Leaderboard	Splits Pi and Oh My Pi into separate leaderboard agent keys and badges.
Docs	Updates supported-agent documentation and architecture notes for Pi / Oh My Pi data sources.

Implementation details

Backend

• Adds Pi / Oh My Pi session scanners in src/data.js.
• Normalizes Pi / Oh My Pi usage fields into Codbash token and cost fields.
• Tracks agent_variant so Pi and Oh My Pi can share the pi tool integration while remaining distinguishable in filters and analytics.
• Stores resume_target for JSONL-backed sessions so resumes can target the exact session file.
• Validates Pi / Oh My Pi resume targets against scanned session files and keeps safe session IDs separate from JSONL resume paths for terminal tracking.
• Extends agent detection, settings validation, CLI listing/resume support, WSL home discovery, active-session detection, markdown export, and terminal launch command construction.

Frontend

• Adds Pi / Oh My Pi labels, badges, filters, sidebar entries, install metadata, and detail actions.
• Wires Pi / Oh My Pi into calendar, heatmap, analytics, leaderboard, and session rendering paths.
• Sends JSONL resume targets for Pi / Oh My Pi detail and project “Last” resume flows.
• Keeps normal UI casing as Pi / Oh My Pi; leaderboard badges remain lowercase (pi, ohmypi) to match existing leaderboard style.

Tests

• Adds Pi / Oh My Pi parser, scanner, nested cache invalidation, resume-target parsing, and leaderboard coverage in test/pi-session.test.js.
• Extends agent detection, settings, sidebar config, frontend escaping, WSL discovery, terminal launch, and Pi feature-parity tests for Pi / Oh My Pi behavior.

Test plan

• node --test
• Focused regression tests: node --test test/pi-session.test.js test/sidebar-config.test.js test/frontend-escaping.test.js
• Isolated dashboard smoke fixture: /api/sessions returns Pi and Oh My Pi JSONL sessions with resume_target.
• Browser smoke: All Sessions renders Pi and Oh My Pi sessions.
• Browser smoke: sidebar filters isolate Pi and Oh My Pi separately.
• Browser smoke: Pi detail view renders messages, model/title context, and Resume action.
• Browser smoke: Resume action sends safe sessionId plus JSONL resumeTarget to /api/launch (fetch intercepted; no real terminal/agent launched).
• Browser smoke: Analytics includes Pi/OhMyPi cost coverage.
• Browser smoke: Leaderboard shows separate pi and ohmypi rows with violet badge styling.
• Manual: click Resume for a real Pi / Oh My Pi session and confirm the terminal resumes it.

Verified locally

• node --test → 142 pass, 0 fail, 2 skipped
• Manual Oh My Pi resume by JSONL path:
  • omp --resume <jsonl path> --print 'respond ok' → ok

Files

• README.md
• docs/ARCHITECTURE.md
• bin/cli.js
• src/agents-detect.js
• src/data.js
• src/frontend/analytics.js
• src/frontend/app.js
• src/frontend/calendar.js
• src/frontend/detail.js
• src/frontend/heatmap.js
• src/frontend/index.html
• src/frontend/leaderboard.js
• src/frontend/sidebar-config.js
• src/frontend/styles.css
• src/server.js
• src/settings.js
• src/terminals.js
• test/agents-detect.test.js
• test/frontend-escaping.test.js
• test/pi-session.test.js
• test/settings.test.js
• test/sidebar-config.test.js
• test/terminals-windows-launch.test.js
• test/wsl-windows.test.js

[timseriakov]

Superseded by #221 using branch feat/pi-agent-support to match the repository branch naming convention.