feat(inception): UI — New-project modal step 2, InceptionCard on the project page, Rules tab shows excluded always-on rulebooks; REST exclusion routes (#2883, milestone 297 step 5)

- components/InceptionCard.vue: the one form, two homes — mode="create" in
  the New-project modal's second step (emits the choices; the create carries
  `inception`), mode="decide" on ProjectView for the owner of an undecided
  project (loads that project's defaults, records the decision). Always-on
  rulebooks listed checked (uncheck = exclude), others unchecked (check =
  subscribe), design system select, seed-Systems toggle (disabled once the
  project has Systems). Tokens only; modal canon (#2855); .btn-* canon.
- ProjectView: the card while undecided, one "Inheritance decided <date> via
  … · …" line after; onDecided refreshes the project.
- ProjectRulesTab: "Excluded always-on rulebooks" section with include-back.
- api/inception.ts (types, fetchInceptionDefaults, decideInception);
  api/rulebooks.ts: ApplicableRules.excluded_always_on, exclude/include
  wrappers; REST POST/DELETE /api/projects/<id>/exclusions/rulebooks/<rb>.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/components/rules/ProjectRulesTab.vue

@@ -2,10 +2,18 @@
 import { ref, onMounted, watch } from "vue";
 import { useRouter } from "vue-router";
 import {
-  getProjectApplicableRules, subscribeProject, unsubscribeProject,
-  listRulebooks, getRule, createProjectRule, deleteRule,
-  suppressRuleForProject, unsuppressRuleForProject,
-  suppressTopicForProject, unsuppressTopicForProject,
+  getProjectApplicableRules,
+  subscribeProject,
+  unsubscribeProject,
+  listRulebooks,
+  getRule,
+  createProjectRule,
+  deleteRule,
+  suppressRuleForProject,
+  unsuppressRuleForProject,
+  suppressTopicForProject,
+  unsuppressTopicForProject,
+  includeAlwaysOnRulebook,
 } from "@/api/rulebooks";
 import type { ApplicableRules, Rulebook } from "@/api/rulebooks";
 
@@ -35,6 +43,11 @@ async function subscribe(rulebookId: number) {
   await load();
 }
 
+async function includeBack(rulebookId: number) {
+  await includeAlwaysOnRulebook(props.projectId, rulebookId);
+  await load();
+}
+
 async function unsubscribe(rulebookId: number) {
   if (!confirm("Unsubscribe from this rulebook for this project?")) return;
   await unsubscribeProject(props.projectId, rulebookId);
@@ -172,6 +185,17 @@ watch(() => props.projectId, load);
       </div>
     </section>
 
+    <section v-if="applicable.excluded_always_on?.length" class="excluded">
+      <h3>Excluded always-on rulebooks</h3>
+      <p class="excluded-note">Opted out at inception — these do not bind this project.</p>
+      <div class="chips">
+        <span v-for="rb in applicable.excluded_always_on" :key="rb.id" class="chip chip-excluded">
+          <a @click="openInRulesView(rb.id)">{{ rb.title }}</a>
+          <button class="chip-remove" @click="includeBack(rb.id)" aria-label="Include again" title="Include again">↩</button>
+        </span>
+      </div>
+    </section>
+
     <section class="project-rules">
       <div class="section-head">
         <h3>Project rules</h3>
@@ -321,6 +345,9 @@ watch(() => props.projectId, load);
 </template>
 
 <style scoped>
+.excluded-note { margin: 0 0 0.5rem; color: var(--fs-text-tertiary); font-size: 0.85rem; }
+.chip-excluded { opacity: 0.8; text-decoration: line-through; }
+.chip-excluded .chip-remove { text-decoration: none; }
 .rules-tab { padding: 1rem; }
 h3 {
   font-size: 0.9em; opacity: 0.7; text-transform: uppercase; letter-spacing: 0.05em;