chore(repo): add BACKERS and CONTRIBUTORS rosters; ignore SBOMs

.gitignore

@@ -63,3 +63,6 @@ docs/
 
 # Auto-generated per-project Claude config
 CLAUDE.md
+
+# CycloneDX SBOMs (generated by the cargo sbom CI workflow per build).
+*.cdx.json

BACKERS.md

@@ -0,0 +1,57 @@
+# Backers
+
+Zagrosi is independently developed and funded by the people and companies listed below. Their support pays for the time that turns a public roadmap into shipped code.
+
+If you find Zagrosi useful, please consider [becoming a sponsor](https://github.com/sponsors/MicrosoftWindows96). Every contribution, monthly or one-time, goes back into the project.
+
+---
+
+## Commercial License sponsors
+
+*$500 per month. Use Zagrosi inside a closed-source product or SaaS without the AGPLv3 source-disclosure obligation. Per-company license covering unlimited internal users.*
+
+<!-- COMMERCIAL_LIST_START -->
+*Reserved.*
+<!-- COMMERCIAL_LIST_END -->
+
+## Operator sponsors
+
+*$100 per month. Priority bug triage and a monthly group office-hours call.*
+
+<!-- OPERATOR_LIST_START -->
+*Reserved.*
+<!-- OPERATOR_LIST_END -->
+
+## Builder sponsors
+
+*$25 per month. Early-access changelog and a vote on quarterly roadmap polls.*
+
+<!-- BUILDER_LIST_START -->
+*Reserved.*
+<!-- BUILDER_LIST_END -->
+
+## Backers
+
+*$5 per month. Sponsor badge on your GitHub profile and a name in this file.*
+
+<!-- BACKER_LIST_START -->
+*Reserved.*
+<!-- BACKER_LIST_END -->
+
+## One-time sponsors
+
+*One-time contributions across the published tiers, including release-note mentions and architecture reviews.*
+
+<!-- ONETIME_LIST_START -->
+*Reserved.*
+<!-- ONETIME_LIST_END -->
+
+---
+
+## How this list is maintained
+
+Sponsors are added by hand on first payment until a webhook bot lands. To opt out of public listing, leave a note in your sponsor message and your support will be kept private.
+
+The marker comments above (for example `<!-- COMMERCIAL_LIST_START -->`) are intentional. A future automation pipeline reads them to insert sponsor entries without touching the surrounding prose.
+
+Order within a tier is reverse-chronological by sponsorship start date.

CONTRIBUTORS.md

@@ -0,0 +1,54 @@
+# Contributors
+
+Zagrosi is the work of the people listed here. Code contributors, design reviewers, security disclosers, founding sponsors, and the wider community of testers and triagers all share the same page.
+
+Code contributors license their work to the maintainer under dual-license terms: AGPLv3 plus an optional commercial license offered to enterprise sponsors. A formal Contributor License Agreement covering this assignment is forthcoming. See [`CONTRIBUTING.md`](CONTRIBUTING.md) for the full workflow.
+
+---
+
+## Maintainer
+
+The lead maintainer goes by the GitHub handle `MicrosoftWindows96`.
+
+## Code contributors
+
+*Listed in order of first merged contribution.*
+
+<!-- CODE_CONTRIBUTORS_START -->
+*No external code contributors yet. Code contribution opens up after the foundation phase ships.*
+<!-- CODE_CONTRIBUTORS_END -->
+
+## Founding sponsors
+
+*Founding Sponsor recognition is reserved for the first wave of supporters once a one-time Founding Sponsor tier is published. Until then, recurring sponsors at every tier are listed in [BACKERS.md](BACKERS.md).*
+
+<!-- FOUNDING_SPONSORS_START -->
+*Reserved.*
+<!-- FOUNDING_SPONSORS_END -->
+
+## Security researchers
+
+*Reported security issues responsibly under the project's disclosure policy.*
+
+<!-- SECURITY_DISCLOSERS_START -->
+*Reserved.*
+<!-- SECURITY_DISCLOSERS_END -->
+
+## Triage and design reviewers
+
+*Filed structured bug reports, reviewed design notes, or moderated discussions.*
+
+<!-- REVIEWERS_START -->
+*Reserved.*
+<!-- REVIEWERS_END -->
+
+---
+
+## How to be added
+
+- **Code contributors** are added by the maintainer when the first pull request lands. The CLA must be signed and the DCO trailer must be present on every commit.
+- **Sponsors** appear in [BACKERS.md](BACKERS.md). Founding Sponsors carry over here once that one-time tier is live.
+- **Security researchers** are added on resolution of a coordinated disclosure. See [`SECURITY.md`](SECURITY.md) for the disclosure flow.
+- **Triage and design reviewers** are nominated by the maintainer based on sustained, public, recognisable contribution.
+
+To opt out of public listing, leave a note when sponsoring or filing a contribution and your involvement will be kept private.