docs: add evaluation readiness index page (#167)

[fredericjasmin]

Summary

Closes #167

Adds a central evaluation-readiness index page that brings together the existing contributor guidance, testing standards, CI guidance, acceptance criteria resources, review checklists, communication guidance, and payment expectations. The new page acts as a navigation hub and is linked from the README documentation index.

Issue scope

Acceptance Criterion	Status	Implementation Evidence	Tests	Notes
Evaluation-readiness index page is added.	✅ Completed	Added docs/EVALUATION_READINESS.md.	N/A (documentation)	Central navigation page.
Payment expectation guide is linked.	✅ Completed	Linked the existing payment expectation documentation.	N/A
Testing standard is linked.	✅ Completed	Linked the existing testing documentation.	N/A
CI guidance is linked.	✅ Completed	Linked the existing CI guidance documentation.	N/A
Acceptance criteria audit is linked.	✅ Completed	Linked the existing acceptance criteria documentation.	N/A
Self-assessment and reviewer checklist are linked.	✅ Completed	Linked the existing contributor self-review and reviewer checklist documentation.	N/A

Affected packages / apps

• apps/web
• packages/types
• packages/config
• packages/fixtures
• packages/validators
• packages/stellar-kit
• packages/anchor-utils
• contracts/treasury-escrow
• docs/
• Other (list):

Testing performed

Commands executed:

• pnpm test ✅ Passed (all TypeScript tests passed)
• pnpm verify ⚠️ Could not complete because the Rust cargo toolchain is unavailable in the current environment.

This PR only introduces documentation changes and does not modify runtime behavior.

Screenshots / recordings

N/A

Security impact

• No security-relevant surface touched.

Documentation impact

• Docs under /docs updated for this change.
• README updated.
• No user-facing behaviour changed — no docs update needed.

Maintainer Review Checklist (self-check)

PR self-check

• References the original issue with Closes #167 in the PR body.
• Acceptance criteria on the issue are checked off individually in the PR description.
• pnpm verify passes locally (Rust toolchain unavailable in the current environment).
• pnpm check:boundaries passes locally (not applicable for this documentation-only change).
• pnpm contract:test passes locally (not applicable).

Stellar network correctness

Not applicable.

Anchor and SEP flow correctness

Not applicable.

Payment intent and readiness correctness

Not applicable.

Soroban contract correctness (if contracts/ changed)

Not applicable.

Secret leakage (R0–R6)

Not applicable.

Mainnet safety

Not applicable.

Tests

Not applicable (documentation-only change).

Documentation

• Topic docs updated.
• README docs index updated.
• Security docs updated if new threat areas introduced.

Risk / follow-ups

None.

Acceptance Criteria Audit

All acceptance criteria for Issue #167 have been completed.

GrantFox payment expectations

Acknowledged.

Contributor self-review

Documentation-only change with a minimal diff. The implementation adds a central evaluation-readiness index page, updates the README documentation index, reuses existing documentation instead of duplicating content, and does not change application behavior.