diff --git a/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/check.jsonl b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/check.jsonl
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+++ b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/check.jsonl
@@ -0,0 +1,12 @@
+{"file": ".opencode/commands/trellis/finish-work.md", "reason": "Finish work checklist"}
+{"file": ".opencode/commands/trellis/check-backend.md", "reason": "Backend check spec"}
+{"file": ".opencode/commands/trellis/check-frontend.md", "reason": "Frontend check spec"}
+{"file": "AGENTS.md", "reason": "Project-level constraints and protocol source of truth"}
+{"file": "apps/AGENTS.md", "reason": "Frontend domain rules and AG-UI alignment"}
+{"file": "backend/AGENTS.md", "reason": "Backend layering and error contract rules"}
+{"file": "docs/protocols/common/http-error-codes.md", "reason": "Cross-layer stable error code registry"}
+{"file": "docs/protocols/agent/api-endpoints.md", "reason": "Agent API and stream contract"}
+{"file": "docs/protocols/agent/sse-events.md", "reason": "SSE event contract between backend and frontend"}
+{"file": "apps/lib/app/di/injection.dart", "reason": "Frontend DI and auth refresh chain patterns"}
+{"file": "apps/lib/data/network/error_code_mapper.dart", "reason": "Frontend error mapping conventions"}
+{"file": "apps/lib/shared/widgets/ui_schema/ui_schema_renderer.dart", "reason": "Frontend UI schema rendering conventions"}
diff --git a/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/debug.jsonl b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/debug.jsonl
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index 0000000..181cbcf
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+++ b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/debug.jsonl
@@ -0,0 +1,2 @@
+{"file": ".opencode/commands/trellis/check-backend.md", "reason": "Backend check spec"}
+{"file": ".opencode/commands/trellis/check-frontend.md", "reason": "Frontend check spec"}
diff --git a/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/implement.jsonl b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/implement.jsonl
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index 0000000..ae8a33d
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+++ b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/implement.jsonl
@@ -0,0 +1,12 @@
+{"file": ".trellis/workflow.md", "reason": "Project workflow and conventions"}
+{"file": ".trellis/spec/backend/index.md", "reason": "Backend development guide"}
+{"file": ".trellis/spec/frontend/index.md", "reason": "Frontend development guide"}
+{"file": "AGENTS.md", "reason": "Project-level constraints and protocol source of truth"}
+{"file": "apps/AGENTS.md", "reason": "Frontend domain rules and AG-UI alignment"}
+{"file": "backend/AGENTS.md", "reason": "Backend layering and error contract rules"}
+{"file": "docs/protocols/common/http-error-codes.md", "reason": "Cross-layer stable error code registry"}
+{"file": "docs/protocols/agent/api-endpoints.md", "reason": "Agent API and stream contract"}
+{"file": "docs/protocols/agent/sse-events.md", "reason": "SSE event contract between backend and frontend"}
+{"file": "apps/lib/app/di/injection.dart", "reason": "Frontend DI and auth refresh chain patterns"}
+{"file": "apps/lib/data/network/error_code_mapper.dart", "reason": "Frontend error mapping conventions"}
+{"file": "apps/lib/shared/widgets/ui_schema/ui_schema_renderer.dart", "reason": "Frontend UI schema rendering conventions"}
diff --git a/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/prd.md b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/prd.md
new file mode 100644
index 0000000..f1d639a
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+++ b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/prd.md
@@ -0,0 +1,21 @@
+# Bootstrap: Fullstack Guidelines (Frontend + Backend + Cross-Layer)
+
+## Goal
+Fill and align Trellis spec docs for frontend, backend, and cross-layer workflows so future AI sessions can follow project-actual conventions across all layers.
+
+## Requirements
+- Create and fill frontend guideline docs under `.trellis/spec/frontend/` based on repository evidence.
+- Keep backend guidelines aligned with current repository conventions and avoid contradiction with previous bootstrap output.
+- Update cross-layer thinking/spec docs to include project-specific contracts and integration checks.
+- Each filled guideline must include practical rules, 2-3 real file path examples, anti-patterns, and explicitly marked unknowns when evidence is weak.
+
+## Acceptance Criteria
+- [ ] Frontend index and core frontend guideline files exist and are populated with project-grounded conventions.
+- [ ] Backend guideline index and docs remain consistent after fullstack pass.
+- [ ] Cross-layer guide(s) include concrete frontend-backend-data contract checkpoints with repository examples.
+- [ ] No placeholder text (`To fill`, `To be filled`) remains in updated spec files.
+
+## Technical Notes
+- Keep scope limited to docs under `.trellis/spec/**` and task metadata/context files.
+- Do not invent framework conventions without code/config/doc evidence.
+- Prefer minimal, reversible edits and keep uncertainties explicit.
diff --git a/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/task.json b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/task.json
new file mode 100644
index 0000000..c85fba3
--- /dev/null
+++ b/.trellis/tasks/archive/2026-04/04-20-bootstrap-fullstack-guidelines/task.json
@@ -0,0 +1,44 @@
+{
+  "id": "bootstrap-fullstack-guidelines",
+  "name": "bootstrap-fullstack-guidelines",
+  "title": "Bootstrap fullstack guidelines",
+  "description": "",
+  "status": "completed",
+  "dev_type": null,
+  "scope": null,
+  "priority": "P2",
+  "creator": "qzl",
+  "assignee": "qzl",
+  "createdAt": "2026-04-20",
+  "completedAt": "2026-04-20",
+  "branch": null,
+  "base_branch": "dev",
+  "worktree_path": null,
+  "current_phase": 2,
+  "next_action": [
+    {
+      "phase": 1,
+      "action": "implement"
+    },
+    {
+      "phase": 2,
+      "action": "check"
+    },
+    {
+      "phase": 3,
+      "action": "finish"
+    },
+    {
+      "phase": 4,
+      "action": "create-pr"
+    }
+  ],
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [],
+  "notes": "",
+  "meta": {}
+}
\ No newline at end of file