docs: rewrite SKILL.md to focus on external project setup (#64)

Restructures SKILL.md to:
- Remove self-development guidance — focus on external project setup
- Clarify that `disinto init` accepts remote URLs or owner/name slugs
- Add project configuration TOML format documentation with field descriptions
- Revise mirror setup section to reference project TOML

Closes #822 and #823 on Codeberg.

---
_Upstream: codeberg johba/disinto PR #824_

Co-authored-by: johba <johba@users.codeberg.org>
Reviewed-on: #64
Reviewed-by: review-bot <review-bot@disinto.local>
Co-authored-by: dev-bot <dev-bot@disinto.local>
Co-committed-by: dev-bot <dev-bot@disinto.local>

disinto-factory/SKILL.md

@@ -9,6 +9,8 @@ You are helping the user set up and operate a **disinto autonomous code factory*
 of bash scripts and Claude CLI that automates the full development lifecycle: picking up
 issues, implementing via Claude, creating PRs, running CI, reviewing, merging, and mirroring.
 
+This guide shows how to set up the factory to develop an **external project** (e.g., `johba/harb`).
+
 ## First-time setup
 
 Walk the user through these steps interactively. Ask questions where marked with [ASK].
@@ -27,20 +29,34 @@ docker --version && git --version && jq --version && curl --version && tmux -V &
 
 Any missing tool — help the user install it before continuing.
 
-### 2. Clone and init
+### 2. Clone disinto and choose a target project
 
+Clone the disinto factory itself:
 ```bash
 git clone https://codeberg.org/johba/disinto.git && cd disinto
 ```
 
-[ASK] What repo should the factory develop? Options:
-- **Itself** (self-development): `bin/disinto init https://codeberg.org/johba/disinto --yes --repo-root $(pwd)`
-- **Another project**: `bin/disinto init <repo-url> --yes`
+[ASK] What repository should the factory develop? Provide the **remote repository URL** in one of these formats:
+- Full URL: `https://github.com/johba/harb.git` or `https://codeberg.org/johba/harb.git`
+- Short slug: `johba/harb` (uses local Forgejo as the primary remote)
 
-Run the init and watch for:
-- All bot users created (dev-bot, review-bot, etc.)
-- `WOODPECKER_TOKEN` generated and saved
-- Stack containers all started
+The factory will clone from the remote URL (if provided) or from your local Forgejo, then mirror to the remote.
+
+Then initialize the factory for that project:
+```bash
+bin/disinto init johba/harb --yes
+# or with full URL:
+bin/disinto init https://github.com/johba/harb.git --yes
+```
+
+The `init` command will:
+- Create all bot users (dev-bot, review-bot, etc.) on the local Forgejo
+- Generate and save `WOODPECKER_TOKEN`
+- Start the stack containers
+- Clone the target repo into the agent workspace
+
+> **Note:** The `--repo-root` flag is optional and only needed if you want to customize
+> where the cloned repo lives. By default, it goes under `/home/agent/repos/<name>`.
 
 ### 3. Post-init verification
 
@@ -70,7 +86,48 @@ docker exec disinto-agents-1 chown -R agent:agent /home/agent/repos
 docker exec -u agent disinto-agents-1 bash -c "source /home/agent/disinto/.env && git clone http://dev-bot:\${FORGE_TOKEN}@forgejo:3000/<org>/<repo>.git /home/agent/repos/<name>"
 ```
 
-### 4. Mirrors (optional)
+### 4. Create the project configuration file
+
+The factory uses a TOML file to configure how it manages your project. Create
+`projects/<name>.toml` based on the template format:
+
+```toml
+# projects/harb.toml
+
+name            = "harb"
+repo            = "johba/harb"
+forge_url       = "http://localhost:3000"
+repo_root       = "/home/agent/repos/harb"
+primary_branch  = "master"
+
+[ci]
+woodpecker_repo_id = 0
+stale_minutes      = 60
+
+[services]
+containers = ["ponder"]
+
+[monitoring]
+check_prs            = true
+check_dev_agent      = true
+check_pipeline_stall = true
+
+# [mirrors]
+# github   = "git@github.com:johba/harb.git"
+# codeberg = "git@codeberg.org:johba/harb.git"
+```
+
+**Key fields:**
+- `name`: Project identifier (used for file names, logs, etc.)
+- `repo`: The source repo in `owner/name` format
+- `forge_url`: URL of your local Forgejo instance
+- `repo_root`: Where the agent clones the repo
+- `primary_branch`: Default branch name (e.g., `main` or `master`)
+- `woodpecker_repo_id`: Set to `0` initially; auto-populated on first CI run
+- `containers`: List of Docker containers the factory should manage
+- `mirrors`: Optional external forge URLs for backup/sync
+
+### 5. Mirrors (optional)
 
 [ASK] Should the factory mirror to external forges? If yes, which?
 - GitHub: need repo URL and SSH key added to GitHub account
@@ -88,7 +145,7 @@ ssh -T git@github.com 2>&1; ssh -T git@codeberg.org 2>&1
 
 If SSH host keys are missing: `ssh-keyscan github.com codeberg.org >> ~/.ssh/known_hosts 2>/dev/null`
 
-Edit `projects/<name>.toml` to add mirrors:
+Edit `projects/<name>.toml` to uncomment and configure mirrors:
 ```toml
 [mirrors]
 github   = "git@github.com:Org/repo.git"
@@ -100,7 +157,7 @@ Test with a manual push:
 source .env && source lib/env.sh && export PROJECT_TOML=projects/<name>.toml && source lib/load-project.sh && source lib/mirrors.sh && mirror_push
 ```
 
-### 5. Seed the backlog
+### 6. Seed the backlog
 
 [ASK] What should the factory work on first? Brainstorm with the user.
 
@@ -128,10 +185,12 @@ Use labels:
 - `blocked` — parked, not for the factory
 - No label — tracked but not for autonomous work
 
-### 6. Watch it work
+### 7. Watch it work
 
 The dev-agent polls every 5 minutes. Trigger manually to see it immediately:
 ```bash
+source .env
+export PROJECT_TOML=projects/<name>.toml
 docker exec -u agent disinto-agents-1 bash -c "cd /home/agent/disinto && bash dev/dev-poll.sh projects/<name>.toml"
 ```