legal: add dual MIT+Apache 2.0 license, trademark policy, and CLA (#941)

- LICENSE: add trademark notice and dual-license reference to MIT file
- LICENSE-APACHE: add full Apache 2.0 license text with ZeroClaw
  trademark clause in section 6
- TRADEMARK.md: define permitted/prohibited uses of the ZeroClaw name,
  list known unauthorized forks (openagen/zeroclaw), and document
  contributor trademark protections
- CLA.md: add Contributor License Agreement granting rights under both
  MIT and Apache 2.0, with explicit patent grant and attribution
  guarantees; contributors retain copyright ownership
- NOTICE: add official repository notice, dual-license summary, and
  contributor protection statement
- README.md: add impersonation warning section with official repo link,
  replace single MIT badge with dual-license table, add trademark and
  contributor protection summary, link CLA.md from Contributing section

TRADEMARK.md

@@ -0,0 +1,129 @@
+# ZeroClaw Trademark Policy
+
+**Effective date:** February 2026  
+**Maintained by:** ZeroClaw Labs
+
+---
+
+## Our Trademarks
+
+The following are trademarks of ZeroClaw Labs:
+
+- **ZeroClaw** (word mark)
+- **zeroclaw-labs** (organization name)
+- The ZeroClaw logo and associated visual identity
+
+These marks identify the official ZeroClaw project and distinguish it from
+unauthorized forks, derivatives, or impersonators.
+
+---
+
+## Official Repository
+
+The **only** official ZeroClaw repository is:
+
+> https://github.com/zeroclaw-labs/zeroclaw
+
+Any other repository, organization, domain, or product claiming to be
+"ZeroClaw" or implying affiliation with ZeroClaw Labs is unauthorized and
+may constitute trademark infringement.
+
+**Known unauthorized forks:**
+- `openagen/zeroclaw` — not affiliated with ZeroClaw Labs
+
+If you encounter an unauthorized use, please report it by opening an issue
+at https://github.com/zeroclaw-labs/zeroclaw/issues.
+
+---
+
+## Permitted Uses
+
+You **may** use the ZeroClaw name and marks in the following ways without
+prior written permission:
+
+1. **Attribution** — stating that your software is based on or derived from
+   ZeroClaw, provided it is clear your project is not the official ZeroClaw.
+
+2. **Descriptive reference** — referring to ZeroClaw in documentation,
+   articles, blog posts, or presentations to accurately describe the software.
+
+3. **Community discussion** — using the name in forums, issues, or social
+   media to discuss the project.
+
+4. **Fork identification** — identifying your fork as "a fork of ZeroClaw"
+   with a clear link to the official repository.
+
+---
+
+## Prohibited Uses
+
+You **may not** use the ZeroClaw name or marks in ways that:
+
+1. **Imply official endorsement** — suggest your project, product, or
+   organization is officially affiliated with or endorsed by ZeroClaw Labs.
+
+2. **Cause brand confusion** — use "ZeroClaw" as the primary name of a
+   competing or derivative product in a way that could confuse users about
+   the source.
+
+3. **Impersonate the project** — create repositories, domains, packages,
+   or accounts that could be mistaken for the official ZeroClaw project.
+
+4. **Misrepresent origin** — remove or obscure attribution to ZeroClaw Labs
+   while distributing the software or derivatives.
+
+5. **Commercial trademark use** — use the marks in commercial products,
+   services, or marketing without prior written permission from ZeroClaw Labs.
+
+---
+
+## Fork Guidelines
+
+Forks are welcome under the terms of the MIT and Apache 2.0 licenses. If
+you fork ZeroClaw, you must:
+
+- Clearly state your project is a fork of ZeroClaw
+- Link back to the official repository
+- Not use "ZeroClaw" as the primary name of your fork
+- Not imply your fork is the official or original project
+- Retain all copyright, license, and attribution notices
+
+---
+
+## Contributor Protections
+
+Contributors to the official ZeroClaw repository are protected under the
+dual MIT + Apache 2.0 license model:
+
+- **Patent grant** (Apache 2.0) — your contributions are protected from
+  patent claims by other contributors.
+- **Attribution** — your contributions are permanently recorded in the
+  repository history and NOTICE file.
+- **No trademark transfer** — contributing code does not transfer any
+  trademark rights to third parties.
+
+---
+
+## Reporting Infringement
+
+If you believe someone is infringing ZeroClaw trademarks:
+
+1. Open an issue at https://github.com/zeroclaw-labs/zeroclaw/issues
+2. Include the URL of the infringing content
+3. Describe how it violates this policy
+
+For serious or commercial infringement, contact the maintainers directly
+through the repository.
+
+---
+
+## Changes to This Policy
+
+ZeroClaw Labs reserves the right to update this policy at any time. Changes
+will be committed to the official repository with a clear commit message.
+
+---
+
+*This trademark policy is separate from and in addition to the MIT and
+Apache 2.0 software licenses. The licenses govern use of the source code;
+this policy governs use of the ZeroClaw name and brand.*