Information Architecture + project/agent visual refresh (experimental) (#7543)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - The board UI is the control surface for issues, projects, agents,
goals, workspaces, and operator settings.
> - The existing navigation and list surfaces make several
high-frequency workflows feel harder to scan than they should,
especially around projects and agents.
> - The product direction is to improve those surfaces without breaking
the existing route model or forcing a new IA on every operator at once.
> - This pull request now keeps the dependent IA, project identity, and
agent-list visual refresh work together while the Issue-to-Task copy
migration is split into #7651.
> - The benefit is a clearer left nav, better project identity, denser
agent/project list rows, and brand-aligned status treatment while
preserving the classic default experience behind a flag.

## Linked Issues or Issue Description

Refs #7645
Refs #7651

Internal planning/work references: PAP-53, PAP-56, PAP-58, PAP-59,
PAP-60, PAP-61, PAP-68, PAP-69, PAP-70, PAP-71, PAP-72, PAP-75, PAP-76,
PAP-80, PAP-85, PAP-86, PAP-87, PAP-88, PAP-89.

## What Changed

- Adds `enableStreamlinedLeftNavigation`, defaulting off, and gates
sidebar presentation so classic navigation remains the default.
- Adds project icon persistence, validation, portability, picker UI, and
`ProjectTile` rendering while defaulting new projects to neutral gray.
- Adds projects-list task-count and budget summary data with focused
server/shared/UI coverage.
- Refreshes agent list rows, row actions, active/recent sidebar
behavior, and status capsule/chip styling for the approved brand state
system.
- Removes the placeholder Conference room and Artifacts nav/routes from
the finalized experimental nav direction.
- Removes `pnpm-lock.yaml` and the Issue-to-Task copy migration from
this PR diff; the copy migration now lives in #7651.

## Verification

- Existing branch verification from the authored commits: UI typecheck,
targeted unit tests, and light/dark visual checks for `/agents`, agent
detail, and design-guide status states.
- Maintainer cleanup verification on `75e34e5`: `git diff --check
origin/master...HEAD` passed, the `design/` diff is empty, and the PR
diff is 61 files, below Greptile's 100-file review limit.
- `pnpm --filter @paperclipai/ui build` passed.
- `NODE_ENV=test pnpm exec vitest run
ui/src/components/Sidebar.test.tsx` passed: 1 file, 8 tests.
- CI and Greptile should rerun on the latest push.

## Risks

- Broad UI surface area: the experimental flag keeps the classic nav
default, but changed shared components such as `EntityRow`,
`ProjectTile`, and agent status badges could affect multiple pages.
- Database migration: `projects.icon` is additive and nullable, but
migration ordering and portability import/export must stay aligned.
- The Issue-to-Task copy migration is now separated into #7651, so
reviewers should evaluate this PR as IA/project/agent presentation work
only.
- Visual regressions are possible across smaller widths because the PR
intentionally changes dense list-row layouts.

## Model Used

Claude Opus 4.8 assisted the original feature commits.
Paperclip-Paperclip agents assisted some planning/design commits. Codex
/ GPT-5-class coding agent with shell, GitHub CLI, and repository access
performed this PR-readiness cleanup and split.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: Dotta <bippadotta@protonmail.com>

ui/src/components/StatusBadge.tsx

@@ -1,5 +1,13 @@
 import { cn } from "../lib/utils";
-import { statusBadge, statusBadgeDefault } from "../lib/status-colors";
+import {
+  statusBadge,
+  statusBadgeDefault,
+  agentStatusColor,
+  agentStatusColorDefault,
+  agentStatusBadge,
+  agentStatusCapsule,
+  agentStatusMotion,
+} from "../lib/status-colors";
 
 export function StatusBadge({ status }: { status: string }) {
   return (
@@ -13,3 +21,39 @@ export function StatusBadge({ status }: { status: string }) {
     </span>
   );
 }
+
+/**
+ * Agent status chip — brand `.task-chip` (1px border, light/dark variants).
+ * Distinct from the shared {@link StatusBadge} so the agents section can carry
+ * the brand state colours without affecting run/issue/goal badges. `active`
+ * renders as "idle" (alias for dead code).
+ */
+export function AgentStatusBadge({ status }: { status: string }) {
+  const color = agentStatusColor[status] ?? agentStatusColorDefault;
+  const label = status === "active" ? "idle" : status;
+  return (
+    <span
+      className={cn(
+        "inline-flex items-center rounded-full border px-3 py-1 text-xs font-medium leading-none whitespace-nowrap shrink-0",
+        agentStatusBadge[color]
+      )}
+    >
+      {label.replace(/_/g, " ")}
+    </span>
+  );
+}
+
+/**
+ * Agent status indicator — brand heartbeat capsule (vertical 8×16, r4). Running
+ * agents pulse, broken (error) agents blink; both honor `prefers-reduced-motion`.
+ */
+export function AgentStatusCapsule({ status }: { status: string }) {
+  const color = agentStatusColor[status] ?? agentStatusColorDefault;
+  const motion = agentStatusMotion[status] ?? "";
+  return (
+    <span
+      aria-hidden
+      className={cn("inline-block h-4 w-2 rounded-[4px] shrink-0", agentStatusCapsule[color], motion)}
+    />
+  );
+}