feat(workspaces): sign the workspace login handoff and gate readiness (#11671)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - Managed worktree services run isolated Paperclip instances with
cloned databases.
> - A reachable service was reported as ready even when its database,
runtime identity, or login path was not usable.
> - The first candidate added verified database seeding and managed
repair in #11665.
> - This pull request consolidates that candidate with signed login
handoff and a complete readiness contract.
> - Post-QA fixes close five defects in repair identity, repair
responses, UI retry, seed journal handling, and seed-source trust.
> - The benefit is a workspace that either opens safely or reports one
accurate recovery action.

## Linked Issues or Issue Description

No public GitHub issue exists for this work, so the problem is described
here.

**What happened**

Managed workspace URLs could return HTTP 200 and report ready while
login failed. QA also found cases where repair used the wrong instance
identity, returned a generic error, left the UI stuck, rejected a safe
journal lag, or trusted a mutable workspace manifest.

**Expected behavior**

Opening a ready workspace signs the board user in to the correct
isolated instance. Provisioning and repair use a registered source and
report a structured recovery state.

**Actual behavior**

Entry depended on a password copied into the clone. Several failure
paths could publish stale readiness, hide the repair precondition, or
trust state that the workspace could modify.

**Additional context**

This pull request includes the commits first published in #11665. That
pull request keeps the original base head for review history. This
consolidated pull request is the merge candidate. Related open readiness
work includes #11575 and #11621.

## What Changed

- Adds a short-lived, signed, single-use login ticket. It binds the
user, workspace, instance, and runtime origin.
- Exchanges the ticket through Better Auth. It creates the session and
cookie through the supported adapter path.
- Adds protected workspace readiness fields for the database, clone
data, login handoff, seed phase, and runtime identity.
- Fails readiness closed when the guest has no company or
execution-workspace binding.
- Binds ticket issuance to the exact cloned user and active company
membership selected for the handoff.
- Verifies every current active board identity through the exact-user
handoff before publication or reuse.
- Gates managed runtime publication on the readiness contract and the
recorded worktree instance identity.
- Refreshes runtime work products from the live runtime row after a port
change.
- Adds one workspace access card with ready, degraded, repairing, and
failed states.
- Uses the runtime response identity for repair. It returns structured
repair precondition errors.
- Lets a valid source journal lag converge during provisioning.
- Binds seed and repair manifests to a source registered outside the
agent-writable worktree.
- Clears recovered UI errors so a successful retry can open the
workspace.
- Makes runtime tests register canonical sources and avoid ports owned
by live host listeners.
- Keeps Vitest on source suites when compiled `dist` trees exist.
- Isolates CLI and adapter tests from ambient AWS and runtime API
environment variables.
- Preserves a 404 response for cross-company workspace ID lookups before
runtime authorization.
- Makes concurrent single-flight coverage independent of
path-canonicalization scheduling order.

## Verification

The following checks passed on the integrated head:

```sh
pnpm -r typecheck
pnpm build
pnpm check:token-gates
pnpm --filter @paperclipai/db check:migrations
```

- The server source lane passed 420 files and 4,953 tests. Five tests
were skipped.
- The CLI lane passed 57 files and 385 tests.
- The database lane passed 26 files and 97 tests.
- The shared package passed 58 files and 506 tests.
- The adapter utility lane passed 640 tests. Four tests were skipped.
- The Claude adapter passed 220 tests. One test was skipped.
- The Codex adapter passed 323 tests.
- The OpenClaw adapter passed 13 tests.
- The OpenCode adapter passed 42 tests.
- The plugin SDK passed 45 tests.
- The workspace runtime suite passed 124 tests.
- The caller-scoped readiness and handoff suite passed 52 tests.
- The workspace provisioning shell suite passed 7 tests.
- The runtime exposure suite passed 17 tests while live host mappings
occupied fixed test ports.
- `git diff --check` passed and the worktree is clean.

The serialized route lane will run in GitHub CI with its normal shards.
No deployment or active-workspace migration was performed.

## Risks

- This is a medium-risk authentication and runtime-readiness change.
- The login ticket uses exact origin, workspace, instance, and user
binding. It has a short expiry and a one-time nonce.
- Runtime publication is stricter. A real readiness, identity, per-user
handoff, or control-plane database disagreement now blocks publication.
- This pull request supersedes #11665 as the merge candidate. Close
#11665 after this pull request merges.
- No new database migration is included. The lockfile and workflow files
are unchanged.
- Deployment and active-workspace migration are intentionally outside
this pull request.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

Claude Opus 5 (`claude-opus-5[1m]`), 1M context, extended thinking, tool
use, and code execution produced the main candidate. OpenAI GPT-5
(`gpt-5`) through Codex, with agentic reasoning, tool use, and code
execution, integrated the post-QA fixes and hardened the test gates. The
Codex context-window size was not exposed.

## 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 not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [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>

scripts/provision-worktree.sh

@@ -8,6 +8,7 @@ paperclip_instance_id="${PAPERCLIP_INSTANCE_ID:-default}"
 paperclip_dir="$worktree_cwd/.paperclip"
 worktree_config_path="$paperclip_dir/config.json"
 worktree_env_path="$paperclip_dir/.env"
+seed_manifest_path="$paperclip_dir/seed-manifest.json"
 seed_pending_marker_path="$paperclip_dir/seed-pending"
 seed_complete_marker_path="$paperclip_dir/seed-complete"
 worktree_name="${PAPERCLIP_WORKSPACE_BRANCH:-$(basename "$worktree_cwd")}"
@@ -39,12 +40,16 @@ if [[ ! -d "$worktree_cwd" ]]; then
   exit 1
 fi
 
-source_config_path="${PAPERCLIP_CONFIG:-}"
-if [[ -z "$source_config_path" && ( -e "$base_cwd/.paperclip/config.json" || -L "$base_cwd/.paperclip/config.json" ) ]]; then
-  source_config_path="$base_cwd/.paperclip/config.json"
+canonical_base_cwd="$(cd "$base_cwd" && pwd -P)"
+source_config_path="$canonical_base_cwd/.paperclip/config.json"
+if [[ ! -f "$source_config_path" || -L "$source_config_path" ]]; then
+  echo "Registered base project workspace has no canonical Paperclip config: $source_config_path" >&2
+  exit 1
 fi
-if [[ -z "$source_config_path" ]]; then
-  source_config_path="$paperclip_home/instances/$paperclip_instance_id/config.json"
+canonical_source_dir="$(cd "$(dirname "$source_config_path")" && pwd -P)"
+if [[ "$canonical_source_dir/config.json" != "$source_config_path" ]]; then
+  echo "Registered base project workspace Paperclip config uses a symlink alias: $source_config_path" >&2
+  exit 1
 fi
 source_env_path="$(dirname "$source_config_path")/.env"
 
@@ -237,25 +242,48 @@ for (const rawValue of runtimePaths) {
 EOF
 }
 
-write_seed_pending_marker() {
+write_seed_pending_manifest() {
+  SEED_MANIFEST_PATH="$seed_manifest_path" \
   SEED_PENDING_MARKER_PATH="$seed_pending_marker_path" \
   SEED_COMPLETE_MARKER_PATH="$seed_complete_marker_path" \
   SOURCE_CONFIG_PATH="$source_config_path" \
+  TARGET_INSTANCE_ID="$worktree_instance_id" \
   node <<'EOF'
+const crypto = require("node:crypto");
 const fs = require("node:fs");
 const path = require("node:path");
 
+const manifestPath = process.env.SEED_MANIFEST_PATH;
 const pendingPath = process.env.SEED_PENDING_MARKER_PATH;
 const completePath = process.env.SEED_COMPLETE_MARKER_PATH;
+const sourceConfigPath = path.resolve(process.env.SOURCE_CONFIG_PATH);
+const sourceEnvPath = path.join(path.dirname(sourceConfigPath), ".env");
+let sourceInstanceId = path.basename(path.dirname(sourceConfigPath));
+if (fs.existsSync(sourceEnvPath)) {
+  const match = fs.readFileSync(sourceEnvPath, "utf8").match(/^\s*(?:export\s+)?PAPERCLIP_INSTANCE_ID\s*=\s*["']?([^\s"'#]+)["']?/m);
+  if (match?.[1]) sourceInstanceId = match[1];
+}
 fs.rmSync(completePath, { force: true });
+fs.rmSync(pendingPath, { force: true });
+const at = new Date().toISOString();
 fs.writeFileSync(
-  pendingPath,
+  manifestPath,
   `${JSON.stringify({
-    version: 1,
-    state: "pending",
-    sourceConfigPath: path.resolve(process.env.SOURCE_CONFIG_PATH),
+    version: 2,
+    source: {
+      instanceId: sourceInstanceId,
+      configPath: sourceConfigPath,
+    },
+    snapshotAt: null,
     seedMode: "minimal",
-    createdAt: new Date().toISOString(),
+    migrationRevision: null,
+    targetInstanceId: process.env.TARGET_INSTANCE_ID,
+    phase: "pending",
+    state: "pending",
+    attemptId: crypto.randomUUID(),
+    startedAt: null,
+    finishedAt: null,
+    diagnostics: [{ phase: "pending", status: "succeeded", at }],
   }, null, 2)}\n`,
   { mode: 0o600 },
 );
@@ -551,8 +579,8 @@ else
   created_worktree_config=1
 fi
 
-if [[ "$created_worktree_config" -eq 1 && ! -e "$seed_pending_marker_path" && ! -e "$seed_complete_marker_path" ]]; then
-  write_seed_pending_marker
+if [[ "$created_worktree_config" -eq 1 && ! -e "$seed_manifest_path" && ! -e "$seed_pending_marker_path" && ! -e "$seed_complete_marker_path" ]]; then
+  write_seed_pending_manifest
 fi
 
 list_base_node_modules_paths() {