vscode: mark recently-created backlog rows with [new] (<24h)

[amrmelsayed]

PIR Review: Mark recently-created backlog rows (< 24h)

Fixes #930

Summary

The Backlog sidebar tree now flags freshly-filed issues: any row whose
createdAt is within the last 24 hours of render-time "now" leads with a
monochrome [new] prefix, and every row with a parseable createdAt gains a
Created <age> line on its hover tooltip. The marker is computed at render
time against a fresh Date.now(), so an item ages out of [new] on the next
tree refresh with no persistent state or per-user dismissal. The [new] text
prefix (rather than an icon swap) was chosen so it coexists with the existing
account / issues assignment icon — the primary goal was letting an engineer
spot a new issue assigned to them, which an icon swap would have hidden.

Files Changed

• packages/vscode/src/views/backlog-recency.ts (+65 / -0) — new, vscode-free
  pure helpers
• packages/vscode/src/__tests__/backlog-recency.test.ts (+82 / -0) — new,
  vitest unit tests
• packages/vscode/src/views/backlog.ts (+12 / -2) — makeRow: [new] label
  prefix + Created <age> tooltip

Commits

• 5ff73ac4 [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Lead row with [new] prefix (before the issue number)
• 54637402 [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Update thread — implement phase
• 0b03226b [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Render [new] prefix + Created-age tooltip on backlog rows
• 417156f9 [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Add backlog-recency pure helpers + unit tests
• 04dcc581 [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Plan revised — follow vscode: builder row legibility — phase prefix + gate-specific icons for at-a-glance protocol/state visibility #810 [new]-prefix pattern
• 93b5768a [PIR vscode: mark recently-created backlog rows (created within last 24h) #930] Plan draft

Test Results

• build (porch check): ✓ pass
• tests (porch check): ✓ pass
• vitest unit suite: ✓ 122 pass (9 new in backlog-recency.test.ts)
• check-types (tsc --noEmit): ✓ pass
• lint (eslint src): ✓ pass
• esbuild bundle: ✓ pass
• Manual verification: approved by the human at the dev-approval gate via the
  running worktree (Extension Development Host / dev server).

Architecture Updates

No arch changes — this is a self-contained, additive change to one view's row
construction (BacklogProvider.makeRow) plus a sibling pure-helper file. It
introduces no new module boundary, data flow, or pattern: it reuses the
established "pure logic in a vscode-free file, vitest-tested in __tests__/,
consumed by the vscode-dependent provider" convention already set by
backlog-filter.ts. codev/resources/arch.md already documents that
convention; nothing to add.

Lessons Learned Updates

No durable lessons captured — the implementation followed existing conventions
end to end (the backlog-filter.ts pure-helper pattern for testability, and
the #810 "monochrome bracket-text prefix coexisting with the row icon" design
language for the marker). One process note worth recording inline rather than
in lessons-learned.md (too situational to generalize): a fresh builder
worktree needs @cluesmith/codev-core and @cluesmith/codev-types built
before the vscode package's tsc/esbuild can resolve their subpath exports —
the first porch done failed the build check for exactly this reason and
passed once core+types were built. This is pre-existing worktree build-ordering
behavior (confirmed via git stash that the status.ts/workspace.ts/
terminal-adapter.ts errors exist without this diff), not introduced here.

3-Way Consultation Disposition (PIR single-pass)

Verdicts: gemini=REQUEST_CHANGES, codex=REQUEST_CHANGES, claude=APPROVE
(full text in codev/projects/930-vscode-mark-recently-created-b/930-review-iter1-*.txt).
PIR consults once — this was not independently re-reviewed, so the human is the
final check at the pr gate.

• [new] placement before #id (gemini + codex) — not a code defect.
  Both flagged that the shipped [new] #<id> <title> order deviates from the
  plan's original #<id> [new] <title>. This was a deliberate revision the
  reviewer requested at the dev-approval gate (commit 5ff73ac4); Claude's
  APPROVE explicitly recognized it as gate-approved. The legitimate kernel was
  plan↔code drift: the approved plan still documented the old order. Fixed
  by reconciling the plan to the shipped order (no code change — the placement
  is the human's gate decision). Gemini's secondary note that leading the row
  with [new] offsets the #id left-alignment for fresh rows is the inherent,
  accepted tradeoff of the requested placement.
• "How to Test Locally" too generic for an extension UI change (codex) —
  valid, addressed. Rewrote that section with concrete Extension Development
  Host steps (build subpath deps → pnpm compile → F5 → open Backlog tree)
  instead of the web-oriented "Run Dev Server" instruction.

Things to Look At During PR Review

• Marker coexists with the assignment icon (backlog.ts:124-130): the
  [new] prefix leads the label while iconPath still dispatches account
  (assigned) vs issues (otherwise). A new + assigned row reads
  👤 [new] #N <title> … assigned to you. This was the resolved design call —
  an earlier draft proposed a $(sparkle) icon swap, rejected because it would
  clobber the assignment icon and hide newness on exactly the rows that matter.
• Robustness of the age parse (backlog-recency.ts): isRecentlyCreated /
  relativeAge both guard Date.parse returning NaN (missing / empty /
  malformed createdAt) and defensively treat future timestamps as
  not-recent / 0s ago. Malformed input yields no prefix and an unchanged
  url-only tooltip — no thrown error. Covered by tests.
• Render-driven, not timer-driven: the marker recomputes only when the
  Backlog tree re-renders (SSE-driven OverviewCache.onDidChange, or a config
  refresh). There is no 24h setTimeout; an item drops [new] on the next
  refresh after crossing the threshold. This matches the issue's acceptance
  criterion Scaling Crisis - AI Autonomy Decreases as Projects Grow #3 ("lose the marker on the next refresh") and was explicitly
  confirmed with the reviewer at the gate.
• Duplicated relative-time format: relativeAge re-implements the ~6-line
  tiered format from view-artifact.ts:135 rather than importing it, because
  that helper lives in a vscode-dependent module and hardcodes Date.now()
  (not injectable for deterministic tests). The format strings match so wording
  stays consistent. A future consolidation could extract a shared
  now-injectable formatter, but that was out of scope here.

How to Test Locally

This is a VSCode extension UI change (the Backlog tree in the Codev
sidebar), so verify it in the Extension Development Host rather than a web dev
server:

1. View diff: VSCode sidebar → right-click builder pir-930 → View Diff.
2. Build the extension: from the worktree, pnpm --filter @cluesmith/codev-core build
   and pnpm --filter @cluesmith/codev-types build (subpath deps), then in
   packages/vscode run pnpm compile.
3. Launch the Extension Development Host: open packages/vscode in VSCode
   and press F5 (Run → Start Debugging), or pick the "Run Extension" launch
   config. A second VSCode window opens with the dev build of the extension.
4. Open the Backlog tree: in the EDH window, open the Codev sidebar and
   expand the Backlog view (connect it to a Tower workspace if prompted, so
   real backlog items load).
5. What to verify:

• A freshly-filed issue (< 24h) leads with [new] before its #id; hovering
  shows Created <Xh ago>.
• A new issue assigned to you keeps its account icon and shows
  [new] plus the assigned to you description (the primary goal).
• An older issue renders unchanged (no [new]); its tooltip still shows
  Created <Xd ago>.
• Mine-only toggle (vscode: backlog view — toggle between 'mine only' (default) and 'all' #809), area grouping (vscode: group backlog by area (area/* label namespace, predictable across views) #811), and the title-count
  formatter (vscode: Backlog tree title-count should reflect the active view mode, not the total spawnable set #911) all still render correctly with [new] prefixes present.
• An issue with missing/malformed createdAt renders with no prefix and a
  url-only tooltip — no error.