Sidebar (replaces the modal drawer):
- Inline, toggleable, no backdrop/focus theft — can stay open while working
- Open state persists across pages (provider in root layout) and reloads
(localStorage; starts closed server-side to avoid hydration mismatch,
stored value applied post-mount; default open on first run)
- Hamburger in page headers only when closed; close button in sidebar header
Floating composer blob (per reference screenshot):
- Floats over the transcript (absolute overlay), persists at bottom while
scrolling, content fades behind it (gradient mask); pb-44 scroll clearance
- Concentric corner radii: blob rounded-2xl(16px) − p-1.5(6px) = send
rounded-[10px] = 25% of the 40px button; CornerDownLeft icon per reference
- Stop moved from header into the blob (busy → square icon)
- prompt-input.tsx + 7 orphan ui files pruned (attachments/command palette
unused); hand-rolled Composer is ~100 lines and render-tested
Pending-question morph (one text field on screen, never two):
- Quiz/ask-select pending → blob becomes the note field (send hidden, hint
line above); card's internal note input removed; Submit consumes it
- Ask free-text pending → blob becomes the answer field; its send submits
via the card's registered submit api (ref bridge); Enter works
- Chat owns the single text state; card clears it on submit
- canSend for answer mode mirrors the card predicate directly — reading the
ref during render lagged one commit (found in browser testing)
Widths: one shared column (max-w-3xl + px-4) for transcript, cards, and
composer — all three measured pixel-identical (left 416, width 736).
Assistant Message max-w-full/MessageContent w-full (was max-w-[95%]/w-fit —
the 'cards are a bit shorter' bug).
User messages render plain text again — no math pipeline on learner-authored
text (currency hazard accepted for the model only, guarded by the prompt).
Tests: 58 pass (5 new composer pins; card tests updated to controlled
props). Verified live: note flow, answer flow, sidebar persistence, float,
fade, zero console errors — plus the live model spontaneously honoring the
$ currency escape contract in a continuation.
Layout:
- Home = knowledge-graph placeholder (main view) with new-session input
docked below; session list moved out of home into a hamburger drawer
- SessionDrawer: slide-over session navigation (backdrop/ESC close, active
highlight, fetches /api/chats on open) on both home and chat headers
- Chat header loses the back button — the drawer is the navigation
Math (inline $ was silently not rendering):
- @streamdown/math defaults singleDollarTextMath:false — now
createMathPlugin({ singleDollarTextMath: true }) in message + reasoning
- katex.min.css imported in layout (streamdown does not inject plugin
styles; display math only looked right via browser MathML fallback)
- QuizCard/AnsweredCard route question/options/explanation through
MessageResponse; user chat bubbles render markdown+math too
- Currency hazard: micromark-extension-math@3.1 lacks pandoc's
closing-digit rule, so bare '$5 and $10' parses as math — defense is at
the source: system prompt now instructs escaped \$5 / 'USD' for money
Hydration fix (React #418):
- QuizCard shuffled options with Math.random() — server/client orders
diverged. shuffleOptions now takes an injectable RNG; QuizCard passes
seededRandom(toolCallId) (mulberry32/FNV-1a in question-core). Same
question → same stable order across reloads; still varies per question.
Tests: 53 pass (5 new math-rendering pins incl. fenced-vs-one-line $$
behavior and the escaped-currency contract). tsc + next build clean.
Verified live in browser: inline/display math in text + cards, drawer
open/navigate/active-highlight/ESC, no console errors, no font 404s.
The teaching agent no longer runs on pi. Stack:
- ToolLoopAgent (ai@7) + OpenRouter (OPENROUTER_API_KEY), model via LH_MODEL,
default anthropic/claude-sonnet-4.5 with reasoning tokens
- quiz/ask_user_question = client-side tools (no server execute): the call
lands as a typed tool part in input-available state; the card grades via
src/core/question-core.ts; addToolOutput sends the verdict; the teacher's
reaction continues the same assistant message
- resume-mid-quiz is free: the pending tool part persists in the transcript
- persistence: one JSON per chat (data/chats/), full UIMessage transcripts,
saved onFinish (also on abort)
- UI: AI Elements (owned copy-paste components, pruned to the five in use)
+ button-based QuizCard/AnsweredCard (ask answers never graded)
- pi fully removed: TUI, extensions, Fastify+WS server, bridge, custom
protocol all deleted (recoverable from git history)
- tests: question-core units carry over; chat-flow integration drives
handleChatRequest with MockLanguageModelV4 (48 tests, zero tokens);
render smoke tests guard the cards (renderToStaticMarkup)
Carried over unchanged: teacher system prompt, question-core, schema/
ledger/derive/extract pipeline, data model.
Root causes of the v1 browser bugs (all fixed + covered by deterministic tests):
- duplicated messages: per-socket snapshot + global broadcast marking raced;
replaced with a single append-only entry log (exactly-once per socket,
structurally) — covered by tests/server.test.ts
- delayed/missing echo of own messages: optimistic append with sending/failed
status, reconciled by text when the real entry arrives
- no thinking shown: thinking deltas streamed live (kind: thinking) and
persisted in assistant entries so they survive reloads
- ask answers graded as wrong: AnsweredCard no longer applies quiz grading to
ask answers (no ✓/✗, no verdict)
- broken option selection: native radio/checkbox inputs fighting React state
replaced with button-based options (single source of truth, one-click select)
- no URLs: History API routing — / home, /s/<file> per session (deep links,
refresh, back button); session view resumes its file on mount
- lost connection = dead UI: exponential-backoff reconnect with full resync
- stick-to-bottom transcript with jump-to-latest pill
Server: startServer() with injectable runtime factory (scripted model in
tests); createSession returns file for routing; scripted model gained thinking
turns. 51 deterministic tests green.