skills: v0.5.0 slim architecture — 3-skill family with validation

/explore (4 Phase), /essence (lens-driven deep dive), /follow (report-dependent guided learning). Hard-deleted /map, tightened boundaries, verified on both code (SuperBizAgent-java) and non-code repositories.

skills/follow/references/env-detect.md

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+# Environment Detection Rules
+
+How to detect the runtime environment and guide the user through setup in `/follow`.
+
+## Language Detection from Config
+
+Check these files in order. The first match is the primary language.
+
+| Config file | Language | Runtime check | Install command |
+|---|---|---|---|
+| `package.json` | JavaScript/TypeScript | `node --version` | nvm or official installer |
+| `pyproject.toml` | Python | `python --version` | pyenv or python.org |
+| `go.mod` | Go | `go version` | golang.org/dl |
+| `Cargo.toml` | Rust | `rustc --version` | rustup |
+| `pom.xml` | Java | `java -version` | SDKMAN or official |
+| `build.gradle` / `build.gradle.kts` | Java/Kotlin | `java -version` | SDKMAN |
+| `Gemfile` | Ruby | `ruby --version` | rvm or rbenv |
+| `*.csproj` | C#/.NET | `dotnet --version` | .NET SDK |
+| `CMakeLists.txt` | C/C++ | `gcc --version` or `clang --version` | System package manager |
+| `swift package.json` | Swift | `swift --version` | Xcode or swift.org |
+
+## Dependency Installation
+
+Once language is detected, guide the user:
+
+### JavaScript/TypeScript
+```bash
+# Check which package manager is used
+if [ -f "yarn.lock" ]; then yarn install
+elif [ -f "pnpm-lock.yaml" ]; then pnpm install
+elif [ -f "bun.lockb" ] || [ -f "bun.lock" ]; then bun install
+else npm install
+fi
+```
+
+### Python
+```bash
+# Modern Python projects
+pip install -e .
+# Or with requirements
+pip install -r requirements.txt
+# Or with poetry
+poetry install
+# Or with uv
+uv pip install -r requirements.txt
+```
+
+### Go
+```bash
+go mod download
+```
+
+### Rust
+```bash
+cargo build
+```
+
+### Java (Maven)
+```bash
+mvn install
+```
+
+### Java (Gradle)
+```bash
+./gradlew build
+# or
+gradle build
+```
+
+## Run Command Detection
+
+How to start the project:
+
+| Source | Command |
+|---|---|
+| `package.json` → `scripts.dev` | `npm run dev` |
+| `package.json` → `scripts.start` | `npm start` |
+| `Makefile` → `dev` target | `make dev` |
+| `Makefile` → `run` target | `make run` |
+| `pyproject.toml` (Poetry) | `poetry run python main.py` |
+| `go.mod` → `package main` | `go run main.go` |
+| `Cargo.toml` → `[[bin]]` | `cargo run` |
+| `docker-compose.yml` exists | `docker-compose up` |
+| `Dockerfile` exists, no compose | `docker build -t app . && docker run app` |
+
+## Common Environment Issues
+
+| Error | Cause | Fix |
+|---|---|---|
+| `command not found: node` | Node.js not installed | Install Node.js (recommend LTS) |
+| `ModuleNotFoundError` | Python deps not installed | Run `pip install -r requirements.txt` |
+| `EACCES: permission denied` | Global install without sudo | Use nvm/fnm, or prefix with sudo |
+| `ENOENT: no such file` | Wrong working directory | `cd` to project root first |
+| `port already in use` | Another process on same port | Kill the process or use different port |
+| `go: cannot find main module` | Outside Go module | `cd` to directory with `go.mod` |
+| `error: could not find Cargo.toml` | Outside Rust project | `cd` to directory with `Cargo.toml` |
+| `java.lang.UnsupportedClassVersionError` | Wrong Java version | Match JDK version to project requirement |
+| `npm ERR! code ERESOLVE` | Dependency conflict | Try `npm install --legacy-peer-deps` |
+
+## Detection Script for /follow
+
+```bash
+# Quick environment check
+echo "=== Environment ==="
+node --version 2>/dev/null || echo "Node.js: not installed"
+python --version 2>/dev/null || echo "Python: not installed"
+go version 2>/dev/null || echo "Go: not installed"
+rustc --version 2>/dev/null || echo "Rust: not installed"
+java -version 2>/dev/null || echo "Java: not installed"
+echo "PWD: $(pwd)"
+```
+
+Run this at the start of `/follow` Step 1 to understand what's available.