Nod chat pane: transcript, work cards, composer and failure banners

[scgopi]

Summary

Nod's chat pane: a loop whose backend surface is .chat opens a chat where a CLI loop's terminal would be, with the same tab strip and splits around it. The layout follows the design's recommendation: 1a's reading column as the base, plus 1b's folded Work block and queued-message row. Stacked on #589 (feat/nod-setup, itself on #583), because the pane uses NodSetup's NodModelCatalog, resolvedModel(for:tier:) and addAllowlistPattern. Rebase onto main once those merge. Retarget this PR before deleting #589's branch, or GitHub closes it. No wire-contract change: NodProtocol.swift and PROTOCOL.md are untouched.

Changes

• NodTranscript: a pure reducer that folds NodEventRecords into turns and cards. It handles:

  • prompts written before or after turnStarted
  • queued messages that start the next turn
  • steers that land in the running turn
  • streamed text, tool results, hunk and permission resolutions
  • goal checks, usage and cost totals, compaction, activity and failures

  Replayed records are dropped. A sessionStarted newer than anything already seen starts a new run, and a turn left open by the old run is closed as interrupted.

• NodChatPresentation: pure view logic.

  • A turn with more than five tool calls folds them into one Work block. Failed calls stay outside the fold.
  • Banners: sign-in expired, context nearly full (from 80%) with Compact now, spend cap.
  • The goal header's verdict, and the cost label: dollars, or premium requests on Copilot.
  • Composer / commands and @ mentions. A running loop is messaged and a finished one has its transcript attached; ⇥ swaps the two.

• NodChatFeature (TCA):

  • ⏎ queues, ⌘⏎ steers, esc closes an open menu first and only then stops Nod.
  • Attachments: files, images, loop transcripts.
  • Card actions: hunk Accept, Reject, or Comment with a note; Allow once, Always or Deny on permission asks; Mark done anyway; fork; Run here, which takes the human-edited plan steps when given; Compact now.
  • Model chip lists NodModelCatalog for the engine and sends setModel. Before the first sessionStarted, the chat shows the model Settings would launch, from resolvedModel(for:tier:).
  • Requests that belong to other streams go up as Delegate actions: Open in zsh tab, edit goal, sign in, raise cap, fork as sibling, run as Composite, /handoff /ask /promote.
  • "Always in project" on a shell ask is saved with NodSettings.addAllowlistPattern, because the runtime keeps Always for the session only.
  • When the runtime refuses fork, sendDraft or runPlan, that action shows disabled rather than as an error.

• NodClient: tails events.jsonl from a byte offset and holds back a torn last line. Sends one NodCommand per connection over control.sock, with send and receive timeouts. A dependency, so tests and renders replay a scripted log.

• Views: goal header pinned with the verdict, which opens to show the clauses. Work cards:

  • tool call, collapsed or open, with Open in zsh tab and Copy output
  • per-hunk diff
  • permission ask
  • native goal check with clauses and evidence
  • fork menu

  Also the composer and its menus, the failure banners, and the steered and queued rows. The composer is an NSTextView because SwiftUI focus cannot take first responder from a Ghostty surface in the same window.

• NodGraphSlots: where NodGraphLayer plugs in, agreed with that stream. Slots: context strip, after-turn, above-composer, inbound mail or handoff in place of the prompt bubble, after-goal-check (handoff offer), plan card, mail draft. All default to nothing.

• Workspace: LoopWorkspaceView draws NodChatPaneView in the agent pane for chat loops. "Open in zsh tab" reuses or creates a plain shell tab and types the command at its prompt without running it (TerminalSurfaceClient.typeText).

Review renders

NodChatRenderTests renders 8 states headless with NSHostingView. Every run lays them out; PNGs are written only when /tmp/nod-chat-renders exists. The states:

1. running pane
2. goal header open, tool card open
3. Work block folded
4. Work block open, commenting on a hunk
5. goal holds, fork menu open
6. the three failure banners
7. composer with attachments, / menu, @ menu
8. graph-layer slots

Test plan

RED: xcodebuild test -only-testing:graphcodeTests/NodTranscriptTests, with the first dedupe rule that let any sessionStarted reset seq -> replayedRecordsAreDroppedButANewRunStartsItsOwnSequence failed: transcript.turns.map(.number) was [1, 1, 2], expected [1, 2], exit 65
GREEN: xcodebuild test for the 7 Nod suites (NodTranscriptTests NodEventTailTests NodComposerMenuTests NodChatFeatureTests NodWorkspaceWiringTests NodControlSocketTests NodChatRenderTests) -> pass, 50 tests on 6254836 plus the state-directory test on c909504
REGRESSION: xcodebuild test, full graphcode scheme, private DerivedData, on c909504 -> pass, 2111 tests in 233 suites, exit 0; on 6254836 graphcode-cli and graphcoded builds exit 0, scripts/cli-smoke.sh exit 0, make check exit 0 (c909504 adds one test only)

Checklist

• I have read the Contributing Guidelines
• I have signed off my commits (git commit -s) per the DCO
• Tests pass locally (full xcodebuild test with private DerivedData, numbers above)
• Code follows the existing style (make check)
• I added the test/contract before the implementation and observed the intended RED failure (tests came with the code; the RED above is a real failure against my first implementation)