feat: 3-option telemetry prompt + community upgrade + regenerate SKILLs

Telemetry prompt now offers Community (backup/benchmarks/email),
Anonymous, or Off. Community tier triggers gstack-auth OTP flow.
Adds one-time upgrade prompt for existing anonymous users.
Preamble emits EMAIL, COMM_PROMPTED, AUTH status vars.
All 33 SKILL.md files regenerated for Claude Code + Codex/agents.

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

scripts/gen-skill-docs.ts

@@ -159,6 +159,12 @@ _TEL_START=$(date +%s)
 _SESSION_ID="$$-$(date +%s)"
 echo "TELEMETRY: \${_TEL:-off}"
 echo "TEL_PROMPTED: $_TEL_PROMPTED"
+_EMAIL=$(${ctx.paths.binDir}/gstack-config get email 2>/dev/null || true)
+_COMM_PROMPTED=$([ -f ~/.gstack/.community-prompted ] && echo "yes" || echo "no")
+_AUTH_OK=$(${ctx.paths.binDir}/gstack-auth-refresh --check 2>/dev/null && echo "yes" || echo "no")
+echo "EMAIL: \${_EMAIL:-none}"
+echo "COMM_PROMPTED: $_COMM_PROMPTED"
+echo "AUTH: $_AUTH_OK"
 mkdir -p ~/.gstack/analytics
 echo '{"skill":"${ctx.skillName}","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true
 for _PF in ~/.gstack/analytics/.pending-*; do [ -f "$_PF" ] && ${ctx.paths.binDir}/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true; break; done
@@ -190,16 +196,31 @@ function generateTelemetryPrompt(ctx: TemplateContext): string {
   return `If \`TEL_PROMPTED\` is \`no\` AND \`LAKE_INTRO\` is \`yes\`: After the lake intro is handled,
 ask the user about telemetry. Use AskUserQuestion:
 
-> gstack can share anonymous usage data (which skills you use, how long they take, crash info)
+> gstack can share usage data (which skills you use, how long they take, crash info)
 > to help improve the project. No code, file paths, or repo names are ever sent.
+>
+> The **community tier** unlocks extra features:
+> - **Cloud backup** of your gstack config + history (restore on new machines)
+> - **Benchmarks**: see how your usage compares to other builders
+> - **Skill recommendations** based on community patterns
+>
 > Change anytime with \`gstack-config set telemetry off\`.
 
 Options:
-- A) Yes, share anonymous data (recommended)
-- B) No thanks
+- A) Community — share data + email for backup, benchmarks & recommendations (recommended)
+- B) Anonymous — share data only, no account
+- C) No thanks
 
-If A: run \`${ctx.paths.binDir}/gstack-config set telemetry anonymous\`
-If B: run \`${ctx.paths.binDir}/gstack-config set telemetry off\`
+If A: ask for their email via a follow-up AskUserQuestion, then run:
+\`\`\`bash
+${ctx.paths.binDir}/gstack-config set telemetry community
+${ctx.paths.binDir}/gstack-auth <user-provided-email>
+\`\`\`
+The auth script will send a verification code to their email. Wait for them to enter the 6-digit code.
+If auth succeeds, continue with the skill. If it fails, fall back to anonymous tier.
+
+If B: run \`${ctx.paths.binDir}/gstack-config set telemetry anonymous\`
+If C: run \`${ctx.paths.binDir}/gstack-config set telemetry off\`
 
 Always run:
 \`\`\`bash
@@ -209,6 +230,35 @@ touch ~/.gstack/.telemetry-prompted
 This only happens once. If \`TEL_PROMPTED\` is \`yes\`, skip this entirely.`;
 }
 
+function generateCommunityUpgradePrompt(ctx: TemplateContext): string {
+  return `If \`TELEMETRY\` is \`anonymous\` AND \`COMM_PROMPTED\` is \`no\`: After the main skill workflow
+begins (not during preamble), offer the community tier upgrade once. Use AskUserQuestion:
+
+> You're already sharing anonymous usage data — nice! Want to unlock more?
+>
+> The **community tier** adds:
+> - Cloud backup of your gstack config (restore on new machines)
+> - Benchmarks: see how your /qa times compare to the community
+> - Skill recommendations based on what other builders use
+>
+> Just needs your email (verified via a one-time code).
+
+Options:
+- A) Yes, join community (enter email)
+- B) Not now
+
+If A: ask for their email, then run \`${ctx.paths.binDir}/gstack-auth <email>\`.
+Wait for the verification code. On success, run \`${ctx.paths.binDir}/gstack-config set telemetry community\`.
+If B: do nothing.
+
+Always run:
+\`\`\`bash
+touch ~/.gstack/.community-prompted
+\`\`\`
+
+This only happens once. If \`COMM_PROMPTED\` is \`yes\`, skip this entirely.`;
+}
+
 function generateAskUserFormat(_ctx: TemplateContext): string {
   return `## AskUserQuestion Format
 
@@ -343,6 +393,7 @@ function generatePreamble(ctx: TemplateContext): string {
     generateUpgradeCheck(ctx),
     generateLakeIntro(),
     generateTelemetryPrompt(ctx),
+    generateCommunityUpgradePrompt(ctx),
     generateAskUserFormat(ctx),
     generateCompletenessSection(),
     generateContributorMode(),