add guide on restoring project after 90-day pause (#44549)

## I have read the
[CONTRIBUTING.md](https://github.com/supabase/supabase/blob/master/CONTRIBUTING.md)
file.

YES

## What kind of change does this PR introduce?

docs update

## What is the new behavior?

How to Restore Project After a 90-Day Pause troubleshooting guide

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Documentation**
* Added a troubleshooting guide for recovering projects paused over 90
days that cannot be restored via the dashboard.
* Describes a step-by-step recovery workflow: export available database
backups and Storage objects, create a replacement project, restore the
database, restore Storage content, and reapply project configurations.
* Notes expected errors during restore, includes an image and video
walkthrough, optional automation script guidance, and links to related
migration and backup/restore guides.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Jeremias Menichelli <jmenichelli@gmail.com>

apps/docs/content/troubleshooting/restore-project-after-90-days-pause.mdx

@@ -0,0 +1,292 @@
+---
+title = "How To Restore Project After 90-Day Pause"
+topics = [ "platform" ]
+keywords = [ "pause", "restore", "90 days", "project", "backup", "migration", "storage" ]
+---
+
+Projects paused for more than 90 days can no longer be restored through Supabase Studio. You can still recover your data by downloading the available backups and migrating them to a new project.
+
+Both the database backup and Storage objects can be downloaded from the [Project Overview](/dashboard/project/_) section in Supabase Studio before the project is deleted.
+
+<Image
+  alt="Restore project after 90-day pause"
+  src={{
+    dark: '/docs/img/restore-after-90-day-dark.png',
+    light: '/docs/img/restore-after-90-day-light.png',
+  }}
+  width={1600}
+  height={900}
+/>
+
+Check this [short video walk-through](https://youtu.be/ktsgm8HxWqo?si=5_8IVzL1rp8MWv7m) of the full migration process.
+
+## Step 1: Download your backups
+
+In the [Project Overview](/dashboard/project/_) of your paused project, download:
+
+- **Database backup** — the `.backup` file from the Backups section
+- **Storage objects** — all files from your Storage buckets
+
+<Admonition type="caution">
+
+Once a project is deleted, all associated data including backups is permanently removed and cannot be recovered.
+
+</Admonition>
+
+## Step 2: Create a new Supabase project
+
+Create a new project at [database.new](https://database.new) and configure it to match your previous setup (extensions, webhooks, Realtime publications, etc.).
+
+## Step 3: Restore the database
+
+Get the **Session pooler** connection string for your new project from the [Connect dialog](/dashboard/project/_?showConnect=true). Replace the `[YOUR-PASSWORD]` placeholder in the connection string with your database password. If you don't remember it, reset it in [Database Settings](/dashboard/project/_/settings/database).
+
+Unzip the downloaded backup file if it has a `.gz` extension, then run:
+
+```bash
+psql -d [CONNECTION_STRING] -f /path/to/backup_file.backup
+```
+
+Some errors like `object already exists` are expected and can be safely ignored — they occur because the new project already has the default Supabase schemas applied.
+
+See the [Restore Dashboard backup guide](/guides/platform/migrating-within-supabase/dashboard-restore) for detailed instructions and troubleshooting.
+
+## Step 4: Restore Storage objects
+
+Use the [Supabase CLI](/docs/reference/cli/introduction) to copy your downloaded storage files to the new project's buckets:
+
+```bash
+supabase login
+supabase link --project-ref [NEW_PROJECT_REF]
+supabase storage cp /path/to/downloaded/files ss:///bucket_name -r --experimental
+```
+
+Repeat for each bucket. See the [`supabase storage cp`](/docs/reference/cli/supabase-storage-cp) reference for all available flags.
+
+## Step 5: Copy project configurations
+
+Use the [Management API](https://api.supabase.com/api/v1) to copy configurations (Auth, Realtime, Storage, etc.) from the paused project to the new one. You need Owner or Admin permissions on both projects.
+
+Get your access token from the [Account Tokens page](/dashboard/account/tokens), then save the script below to a file and make it executable:
+
+```bash
+chmod +x sync_supabase_config.sh
+```
+
+<Accordion
+  type="default"
+  openBehaviour="multiple"
+  chevronAlign="right"
+  justified
+  size="medium"
+  className="text-foreground-light mt-8 mb-6"
+>
+  <div className="border-b mt-3 pb-3">
+    <AccordionItem
+      header="Config sync script"
+      id="config-sync-script"
+    >
+
+```bash
+#!/usr/bin/env bash
+set -euo pipefail
+
+# ---------------------------------------------------------------------------
+# Sync Supabase project configuration from a SOURCE project to a TARGET project
+# using the Supabase Management API.
+#
+# Usage:
+#   export SUPABASE_ACCESS_TOKEN="sbp_..."
+#   ./sync_supabase_config.sh <source_ref> <target_ref> [--dry-run]
+#
+# Options:
+#   --dry-run   Fetch and diff configs without applying changes to the target.
+#
+# Output:
+#   Saves source and target configs to ./config_sync_<timestamp>/ so you can
+#   review exactly what was (or would be) changed.
+# ---------------------------------------------------------------------------
+
+API_BASE="https://api.supabase.com/v1"
+
+SOURCE_REF="${1:?Usage: $0 <source_ref> <target_ref> [--dry-run]}"
+TARGET_REF="${2:?Usage: $0 <source_ref> <target_ref> [--dry-run]}"
+DRY_RUN="${3:-}"
+
+TOKEN="${SUPABASE_ACCESS_TOKEN:?Set SUPABASE_ACCESS_TOKEN environment variable}"
+
+AUTH_HEADER="Authorization: Bearer ${TOKEN}"
+CONTENT_TYPE="Content-Type: application/json"
+
+if ! command -v jq &>/dev/null; then
+  echo "Error: jq is required but not installed." >&2
+  exit 1
+fi
+
+# Configs to sync: "label|get_path|update_method|update_path"
+# pgbouncer is read-only so it is excluded.
+CONFIGS=(
+  "Auth|/config/auth|PATCH|/config/auth"
+  "Realtime|/config/realtime|PATCH|/config/realtime"
+  "Database Pooler|/config/database/pooler|PATCH|/config/database/pooler"
+  "Database Postgres|/config/database/postgres|PUT|/config/database/postgres"
+  "PostgREST|/postgrest|PATCH|/postgrest"
+  "Storage|/config/storage|PATCH|/config/storage"
+)
+
+# ---------------------------------------------------------------------------
+# Per-config payload transforms applied before PATCH/PUT.
+# Each function reads JSON from stdin and writes cleaned JSON to stdout.
+# ---------------------------------------------------------------------------
+transform_Auth() {
+  jq 'with_entries(
+    .key as $k |
+    select(
+      (["rate_limit_email_sent", "rate_limit_sms_sent",
+        "security_captcha_secret", "nimbus_oauth_client_secret",
+        "db_max_pool_size", "db_max_pool_size_unit",
+        "api_max_request_duration",
+        "sessions_single_per_user", "sessions_tags"
+      ] | index($k)) == null
+      and ($k | test("^(smtp_|sms_messagebird_|sms_textlocal_|sms_twilio_|sms_vonage_|sms_test_otp|hook_mfa_verification_attempt_|hook_password_verification_attempt_)") | not)
+      and ($k | test("passkey|web_?authn") | not)
+      and ($k | test("_secrets?$") | not)
+    )
+  )'
+}
+
+transform_Database_Pooler() {
+  jq 'if type == "array" then .[0] else . end
+      | {default_pool_size, pool_mode}
+      | with_entries(select(.value != null))'
+}
+
+transform_PostgREST() {
+  jq 'with_entries(select(.value != null))'
+}
+
+transform_Storage() {
+  jq 'del(.capabilities, .migrationVersion, .databasePoolMode, .features)'
+}
+
+transform_payload() {
+  local label="$1"
+  local func_name="transform_${label// /_}"
+  if declare -f "$func_name" &>/dev/null; then
+    "$func_name"
+  else
+    cat
+  fi
+}
+
+TMPDIR=$(mktemp -d)
+trap 'rm -rf "$TMPDIR"' EXIT
+
+OUTDIR="./config_sync_$(date +%Y%m%d_%H%M%S)"
+mkdir -p "$OUTDIR"
+
+echo "============================================="
+echo "  Supabase Config Sync"
+echo "  Source : ${SOURCE_REF}"
+echo "  Target : ${TARGET_REF}"
+echo "  Output : ${OUTDIR}"
+[[ "$DRY_RUN" == "--dry-run" ]] && echo "  Mode   : DRY RUN (no changes applied)"
+echo "============================================="
+echo
+
+for entry in "${CONFIGS[@]}"; do
+  IFS='|' read -r label get_path method update_path <<< "$entry"
+  safe_label="${label// /_}"
+
+  echo "--- ${label} ---"
+
+  # Fetch source config
+  source_file="${OUTDIR}/${safe_label}_source.json"
+  http_code=$(curl -s -o "$source_file" -w "%{http_code}" \
+    "${API_BASE}/projects/${SOURCE_REF}${get_path}" \
+    -H "$AUTH_HEADER")
+
+  if [[ "$http_code" != "200" ]]; then
+    echo "  [SKIP] GET source failed (HTTP ${http_code})"
+    echo
+    continue
+  fi
+
+  # Fetch target config
+  target_file="${OUTDIR}/${safe_label}_target.json"
+  http_code_target=$(curl -s -o "$target_file" -w "%{http_code}" \
+    "${API_BASE}/projects/${TARGET_REF}${get_path}" \
+    -H "$AUTH_HEADER")
+
+  if [[ "$http_code_target" != "200" ]]; then
+    echo "  [SKIP] GET target failed (HTTP ${http_code_target})"
+    echo
+    continue
+  fi
+
+  echo "  [OK]   Fetched both configs"
+
+  # Build transformed payload
+  payload_file="${TMPDIR}/${safe_label}_payload.json"
+  transform_payload "$label" < "$source_file" > "$payload_file"
+
+  # Skip if the transformed payload is empty (source had no usable config)
+  if [[ "$(jq 'length' "$payload_file")" == "0" ]]; then
+    echo "  [SKIP] Source config is empty — nothing to apply"
+    echo
+    continue
+  fi
+
+  # Pretty-print both sides and diff
+  source_pretty="${TMPDIR}/${safe_label}_src_pretty.json"
+  target_pretty="${TMPDIR}/${safe_label}_tgt_pretty.json"
+  jq --sort-keys . "$payload_file"  > "$source_pretty"
+  jq --sort-keys . "$target_file"   > "$target_pretty"
+
+  if diff -q "$source_pretty" "$target_pretty" &>/dev/null; then
+    echo "  [=]    No differences"
+  else
+    echo "  [~]    Differences (source → target):"
+    diff --unified=3 "$target_pretty" "$source_pretty" | sed 's/^/         /' || true
+  fi
+
+  if [[ "$DRY_RUN" == "--dry-run" ]]; then
+    echo
+    continue
+  fi
+
+  # Apply to target
+  update_response="${TMPDIR}/${safe_label}_response.json"
+  update_code=$(curl -s -o "$update_response" -w "%{http_code}" \
+    -X "$method" \
+    "${API_BASE}/projects/${TARGET_REF}${update_path}" \
+    -H "$AUTH_HEADER" \
+    -H "$CONTENT_TYPE" \
+    -d @"$payload_file")
+
+  if [[ "$update_code" =~ ^2 ]]; then
+    echo "  [OK]   Applied to target (HTTP ${update_code})"
+  else
+    echo "  [FAIL] ${method} failed (HTTP ${update_code})"
+    cat "$update_response"
+    echo
+  fi
+
+  echo
+done
+
+echo "Done. Configs saved to ${OUTDIR}/"
+```
+
+    </AccordionItem>
+
+  </div>
+</Accordion>
+
+The script saves both source and target configs to a local `config_sync_<timestamp>/` directory so you can review exactly what changed. Use `--dry-run` to preview differences without applying them.
+
+## Related guides
+
+- [Migrating within Supabase](/guides/platform/migrating-within-supabase)
+- [Restore Dashboard backup](/guides/platform/migrating-within-supabase/dashboard-restore)
+- [Backup and Restore using the CLI](/guides/platform/migrating-within-supabase/backup-restore)