Assisted-by: Claude Opus 4.6 via pi

diff --git a/AGENTS.md b/AGENTS.md
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@@ -0,0 +1,39 @@
+# Agents
+
+Read the README for project context, domain concepts, and design intent.
+
+## Layout
+
+```
+lib/
+  config.rb        # Config Data object, reads DATABASE_URL from env
+  db.rb            # Sequel connection + auto-migration
+  web.rb           # Roda app (routes, current_user from Tailscale headers)
+  views/
+    layout.rb      # Phlex base layout
+    series/
+      new.rb       # New series form
+db/
+  migrate/         # Sequel migrations (numbered)
+test/
+  test_web.rb      # Minitest integration tests
+public/
+  css/             # Static assets
+```
+
+## Running
+
+```sh
+rake           # runs tests + binstubs (default)
+rake test      # tests only
+rake dev       # starts dev server with Tailscale serve + auto-restart via entr
+```
+
+Tests set `DATABASE_URL=:memory:` so they never touch the real database.
+
+## Conventions
+
+- **Views:** Phlex component classes under `lib/views/`, not ERB templates.
+- **Migrations:** Sequel migrations in `db/migrate/`, numbered sequentially (`001_`, `002_`, …). Migrations auto-run on boot.
+- **User identification:** Current user comes from `HTTP_TAILSCALE_USER_LOGIN` / `HTTP_TAILSCALE_USER_NAME` request headers.
+- **Testing:** Minitest with `Rack::Test`. Fake Tailscale headers via helper.
diff --git a/README.md b/README.md
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--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ A personal/family tool for tracking recurring tasks and catching up on what's ov
 
 ## Key concepts
 
-- **Tasks** are recurring, with a configurable interval (day/week/month) and interval count
+- **Tasks** are recurring, with a configurable interval (day/week/month/quarter/year) and interval count
   - Recurrence is based on interval+count from last completion (not fixed schedule — but may add fixed schedule later)
 - Each user has their own tasks
 - Tasks can also be **shared** — visible to all users, anyone can mark them done, overdue shows for everyone
@@ -23,7 +23,7 @@ A personal/family tool for tracking recurring tasks and catching up on what's ov
 ## Task fields
 
 - **Note** — free text; first line serves as the task name/title
-- **Interval unit** — day, week, or month
+- **Interval unit** — day, week, month, quarter, or year
 - **Interval count** — e.g., 2 (combined with unit: "every 2 weeks")
 - **First due date** — user picks this on creation
 - **Personal or shared**