feat: auto-clone tapestries template + viewer setup reference

felt tapestry export now offers to clone the template repo if
~/.felt/tapestries/ doesn't exist. Added references/viewer-setup.md
to the tapestry skill covering local serving, GitHub Pages, and
data layout.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: cailmdaley

cmd/skills/tapestry/SKILL.md

@@ -141,3 +141,7 @@ A tapestry grows through phases, and you can't skip them:
 3. **Living** — the tapestry continues to grow. New analyses add nodes; shaping keeps the narrative coherent.
 
 A constitution (see `/constitution`) can drive each phase.
+
+## References
+
+- [references/viewer-setup.md](references/viewer-setup.md) — cloning the template, serving locally, GitHub Pages, data layout

cmd/skills/tapestry/references/viewer-setup.md

@@ -0,0 +1,83 @@
+# Tapestry Viewer Setup
+
+The tapestry viewer is a static site that renders felt DAGs as navigable graphs. It lives in a standalone repo that you clone once; `felt tapestry export` writes data into it.
+
+## First Time
+
+```bash
+felt tapestry export    # auto-clones the template if ~/.felt/tapestries/ doesn't exist
+```
+
+Or manually:
+
+```bash
+git clone --depth 1 https://github.com/cailmdaley/tapestries.git ~/.felt/tapestries
+```
+
+## Exporting
+
+From any project with `.felt/` fibers and `tapestry:` tags:
+
+```bash
+felt tapestry export                  # writes to ~/.felt/tapestries/data/{project}/
+felt tapestry export --all-fibers     # include all fibers for sidebar
+felt tapestry export --force          # re-copy all artifacts
+felt tapestry export --name foo       # override project name
+felt tapestry export --out /path/     # override output directory
+```
+
+## Serving Locally
+
+```bash
+npx serve -s ~/.felt/tapestries
+```
+
+Open `http://localhost:3000`. The landing page lists available tapestries from `data/manifest.json`.
+
+## GitHub Pages
+
+1. Create a new repo from the [tapestries template](https://github.com/cailmdaley/tapestries)
+2. Enable Pages: Settings → Pages → Deploy from branch `main`, folder `/`
+3. Export and push:
+
+```bash
+felt tapestry export --out /path/to/your-repo/data/myproject
+cd /path/to/your-repo
+git add -A && git commit -m "update tapestry" && git push
+```
+
+Your tapestries will be at `https://<user>.github.io/<repo>/`.
+
+## Data Layout
+
+```
+~/.felt/tapestries/
+  index.html                    # viewer (from template, rarely changes)
+  assets/                       # JS/CSS bundles
+  data/
+    manifest.json               # city list (auto-updated by export)
+    myproject/
+      tapestry.json             # DAG: nodes, links, evidence, staleness
+      tapestry/                 # artifact images
+        specname/
+          figure.png
+      files/                    # linked files (optional)
+```
+
+## Keeping History Small
+
+Artifact images accumulate. To cap repo size, periodically squash history:
+
+```bash
+cd ~/.felt/tapestries
+KEEP=5
+COUNT=$(git rev-list --count HEAD)
+if [ "$COUNT" -gt "$KEEP" ]; then
+  CUTPOINT=$(git rev-list HEAD | sed -n "${KEEP}p")
+  REMOTE_URL=$(git remote get-url origin)
+  git replace --graft "$CUTPOINT"
+  git filter-repo --force --quiet
+  git remote add origin "$REMOTE_URL"
+  git push --force --set-upstream origin main
+fi
+```

cmd/tapestry.go

@@ -1,9 +1,12 @@
 package cmd
 
 import (
+	"bufio"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 
 	"github.com/cailmdaley/felt/internal/felt"
 	"github.com/cailmdaley/felt/internal/tapestry"
@@ -68,6 +71,8 @@ func init() {
 	tapestryExportCmd.Flags().StringVar(&tapestryOut, "out", "", "Override output directory")
 }
 
+const tapestriesTemplateURL = "https://github.com/cailmdaley/tapestries.git"
+
 func defaultTapestriesRepo() (string, error) {
 	home, err := os.UserHomeDir()
 	if err != nil {
@@ -79,8 +84,24 @@ func defaultTapestriesRepo() (string, error) {
 		return repoDir, nil
 	}
 
-	return "", fmt.Errorf(
-		"No tapestries repo found at %s/\nClone it: git clone git@github.com:cailmdaley/tapestries.git %s",
-		repoDir, repoDir,
-	)
+	fmt.Printf("No tapestries repo found at %s/\n", repoDir)
+	fmt.Printf("Clone the template viewer? [Y/n] ")
+	reader := bufio.NewReader(os.Stdin)
+	answer, _ := reader.ReadString('\n')
+	answer = strings.TrimSpace(strings.ToLower(answer))
+	if answer != "" && answer != "y" && answer != "yes" {
+		return "", fmt.Errorf("aborted")
+	}
+
+	fmt.Printf("Cloning %s...\n", tapestriesTemplateURL)
+	clone := exec.Command("git", "clone", "--depth", "1", tapestriesTemplateURL, repoDir)
+	clone.Stdout = os.Stdout
+	clone.Stderr = os.Stderr
+	if err := clone.Run(); err != nil {
+		return "", fmt.Errorf("clone failed: %w", err)
+	}
+
+	fmt.Printf("Tapestries viewer ready at %s\n", repoDir)
+	fmt.Println("Serve locally: npx serve -s " + repoDir)
+	return repoDir, nil
 }