Squashed commit of the following:

commit 1eeea9f83ad9230a5c1f7a75662770eaab0df837
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 21:15:41 2025 +0200

    Disable resuming of old time entries.

commit 3e3ec2f01cb7943622b819a19179388078ae1315
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 20:59:19 2025 +0200

    Refactor db migrations.

commit 15a51a569da36c6b7c9e01ab17b6fdbdee6ad994
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 19:58:04 2025 +0200

    Apply new style for Time Tracking view.

commit 77e5278b303e060d2b03853b06277f8aa567ae68
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 18:06:04 2025 +0200

    Allow direct registrations as a Company.

commit 188a8772757cbef374243d3a5f29e4440ddecabe
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 18:04:45 2025 +0200

    Add email invitation feature.

commit d9ebaa02aa01b518960a20dccdd5a327d82f30c6
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 17:12:32 2025 +0200

    Apply common style for Company, User, Team management pages.

commit 81149caf4d8fc6317e2ab1b4f022b32fc5aa6d22
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 16:44:32 2025 +0200

    Move export functions to own module.

commit 1a26e19338e73f8849c671471dd15cc3c1b1fe82
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 15:51:15 2025 +0200

    Split up models.py.

commit 61f1ccd10f721b0ff4dc1eccf30c7a1ee13f204d
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 12:05:28 2025 +0200

    Move utility function into own modules.

commit 84b341ed35e2c5387819a8b9f9d41eca900ae79f
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 11:44:24 2025 +0200

    Refactor auth functions use.

commit 923e311e3da5b26d85845c2832b73b7b17c48adb
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 11:35:52 2025 +0200

    Refactor route nameing and fix bugs along the way.

commit f0a5c4419c340e62a2615c60b2a9de28204d2995
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 10:34:33 2025 +0200

    Fix URL endpoints in announcement template.

commit b74d74542a1c8dc350749e4788a9464d067a88b5
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 09:25:53 2025 +0200

    Move announcements to own module.

commit 9563a28021ac46c82c04fe4649b394dbf96f92c7
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 09:16:30 2025 +0200

    Combine Company view and edit templates.

commit 6687c373e681d54e4deab6b2582fed5cea9aadf6
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 08:17:42 2025 +0200

    Move Users, Company and System Administration to own modules.

commit 8b7894a2e3eb84bb059f546648b6b9536fea724e
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 07:40:57 2025 +0200

    Move Teams and Projects to own modules.

commit d11bf059d99839ecf1f5d7020b8c8c8a2454c00b
Author: Jens Luedicke <jens@luedicke.me>
Date:   Mon Jul 7 07:09:33 2025 +0200

    Move Tasks and Sprints to own modules.

migrations/old_migrations/19_add_company_invitations.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""
+Add company invitations table for email-based registration
+"""
+
+import sys
+import os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from flask import Flask
+from models import db
+from sqlalchemy import text
+import logging
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+def migrate():
+    """Add company_invitation table"""
+    app = Flask(__name__)
+    app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get('DATABASE_URL', 'sqlite:////data/timetrack.db')
+    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
+    
+    db.init_app(app)
+    
+    with app.app_context():
+        try:
+            # Create company_invitation table
+            create_table_sql = text("""
+                CREATE TABLE IF NOT EXISTS company_invitation (
+                    id SERIAL PRIMARY KEY,
+                    company_id INTEGER NOT NULL REFERENCES company(id),
+                    email VARCHAR(120) NOT NULL,
+                    token VARCHAR(64) UNIQUE NOT NULL,
+                    role VARCHAR(50) DEFAULT 'Team Member',
+                    invited_by_id INTEGER NOT NULL REFERENCES "user"(id),
+                    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+                    expires_at TIMESTAMP NOT NULL,
+                    accepted BOOLEAN DEFAULT FALSE,
+                    accepted_at TIMESTAMP,
+                    accepted_by_user_id INTEGER REFERENCES "user"(id)
+                );
+            """)
+            
+            db.session.execute(create_table_sql)
+            
+            # Create indexes for better performance
+            db.session.execute(text("CREATE INDEX IF NOT EXISTS idx_invitation_token ON company_invitation(token);"))
+            db.session.execute(text("CREATE INDEX IF NOT EXISTS idx_invitation_email ON company_invitation(email);"))
+            db.session.execute(text("CREATE INDEX IF NOT EXISTS idx_invitation_company ON company_invitation(company_id);"))
+            db.session.execute(text("CREATE INDEX IF NOT EXISTS idx_invitation_expires ON company_invitation(expires_at);"))
+            
+            db.session.commit()
+            logger.info("Successfully created company_invitation table")
+            
+            return True
+            
+        except Exception as e:
+            logger.error(f"Error creating company_invitation table: {str(e)}")
+            db.session.rollback()
+            return False
+
+if __name__ == '__main__':
+    success = migrate()
+    sys.exit(0 if success else 1)