chore: consolidate documentation — delete status/fix/progress cruft

Before: 335 tracked .md files; top level had 14 README-like docs;
docs/ contained ~234 files, most of them auto/LLM-generated status
reports (ALL_*_COMPLETE*, *_FIX*, DEPLOYMENT_*_FINAL*, etc.).

After: 132 tracked .md files. Repo now has exactly five top-level
docs: README.md, QUICKSTART.md, RUNBOOK.md, CONTRIBUTING.md,
CHANGELOG.md (moved up from docs/).

Keeper philosophy in docs/:
- API, CCIP (ops + security + receiver/router refs), Chainlist refs,
  compliance, deployment (guides not status), database connection,
  legal compliance, metamask integration, production checklist,
  tiered-architecture implementation/setup, reusable-components plan,
  token-mechanism doc, wrap-and-bridge operational reference, plus
  docs/specs/** and docs/api/ / docs/openapi/ trees.

Deleted (git history preserves provenance):
- All 'ALL_*_COMPLETE*' / '*_FIX*' / '*_FIXED*' / '*_FINAL*' /
  '*_STATUS*' / '*_PROGRESS*' / '*_SUMMARY*' files.
- BLOCKSCOUT_*_FIX / _CRASH / _INITIALIZATION / _SCHEMA / _YAML /
  _SKIP / _NEXT_STEPS / _START_AND_BUILD / _DATABASE_CREDENTIALS
  (the last contained passwords).
- CCIP_IMPLEMENTATION_* / CCIP_CURRENT_STATUS / CCIP_GAP_*
  (gap analyses are not a sustained reference).
- NPMPLUS_CREDENTIALS_GUIDE.md (contained creds).
- LETSENCRYPT_CONFIGURATION_GUIDE.md (contained creds; will be
  re-introduced as runbook content post-secrets-scrub).
- docs/diagnostic-reports/, docs/feature-flags/ (run-time artifacts).

README.md: dead links (START_HERE, README_DEPLOYMENT, COMPLETE_DEPLOYMENT,
DEPLOYMENT_COMPLETE_FINAL) replaced with links to the five canonical
top-level docs + docs/ index.

docs/DATABASE_PASSWORD_FIX.md

@@ -1,138 +0,0 @@
-# Database Password Fix Guide
-
-## Problem
-The backend API is returning HTTP 503 with a "degraded" status because it cannot connect to the PostgreSQL database. The error message indicates:
-```
-password authentication failed for user "explorer" (SQLSTATE 28P01)
-```
-
-## Solution
-
-The database password needs to be reset to match the backend configuration. The backend expects:
-- **User**: `explorer`
-- **Password**: `changeme`
-- **Database**: `explorer`
-
-### Option 1: Automated Fix (Recommended)
-
-Run the fix script with sudo:
-
-```bash
-cd /home/intlc/projects/proxmox/explorer-monorepo
-sudo ./scripts/fix-database-password-manual.sh
-```
-
-This script will:
-1. Create or update the `explorer` PostgreSQL user with password `changeme`
-2. Create the `explorer` database if it doesn't exist
-3. Grant all privileges to the explorer user
-4. Test the connection
-
-### Option 2: Manual Fix
-
-If you prefer to fix it manually, run these commands:
-
-```bash
-# Connect to PostgreSQL as the postgres superuser
-sudo -u postgres psql
-
-# In the PostgreSQL prompt, run:
-CREATE USER explorer WITH PASSWORD 'changeme';
-CREATE DATABASE explorer OWNER explorer;
-GRANT ALL PRIVILEGES ON DATABASE explorer TO explorer;
-\q
-```
-
-Or if the user already exists:
-
-```bash
-sudo -u postgres psql -c "ALTER USER explorer WITH PASSWORD 'changeme';"
-sudo -u postgres psql -c "GRANT ALL PRIVILEGES ON DATABASE explorer TO explorer;"
-```
-
-### Option 3: Use Different Password
-
-If you want to use a different password, you have two options:
-
-**A. Update the backend to use the existing password:**
-
-```bash
-export DB_PASSWORD="your_actual_password"
-kill $(cat /tmp/explorer_backend.pid) 2>/dev/null
-./scripts/start-backend-service.sh
-```
-
-**B. Change the database password to match backend:**
-
-```bash
-sudo -u postgres psql -c "ALTER USER explorer WITH PASSWORD 'your_new_password';"
-export DB_PASSWORD="your_new_password"
-kill $(cat /tmp/explorer_backend.pid) 2>/dev/null
-./scripts/start-backend-service.sh
-```
-
-## Verification
-
-After fixing the password, verify the connection:
-
-```bash
-# Test database connection
-PGPASSWORD=changeme psql -h localhost -U explorer -d explorer -c "SELECT 1;"
-
-# Check backend health
-curl http://localhost:8080/health
-
-# Expected response should show:
-# "database": "ok" (instead of "error: ...")
-# "status": "ok" (instead of "degraded")
-```
-
-## Restart Backend
-
-After fixing the password, restart the backend:
-
-```bash
-kill $(cat /tmp/explorer_backend.pid) 2>/dev/null
-./scripts/start-backend-service.sh
-```
-
-## Troubleshooting
-
-### PostgreSQL not running
-```bash
-sudo systemctl status postgresql
-sudo systemctl start postgresql
-```
-
-### User doesn't exist
-```bash
-sudo -u postgres psql -c "\du"  # List all users
-```
-
-### Database doesn't exist
-```bash
-sudo -u postgres psql -c "\l"  # List all databases
-```
-
-### Connection still failing
-1. Check PostgreSQL is listening on port 5432:
-   ```bash
-   netstat -tlnp | grep 5432
-   ```
-
-2. Check PostgreSQL authentication configuration:
-   ```bash
-   sudo cat /etc/postgresql/*/main/pg_hba.conf | grep -v "^#"
-   ```
-
-3. Verify the password was actually changed:
-   ```bash
-   PGPASSWORD=changeme psql -h localhost -U explorer -d explorer -c "SELECT current_user;"
-   ```
-
-## Notes
-
-- The default password `changeme` is used for development. **Change it in production!**
-- The backend reads the password from the `DB_PASSWORD` environment variable
-- If using Docker Compose, the password is set via the `DB_PASSWORD` environment variable in `deployment/docker-compose.yml`
-