Prepare Deja Vu for an adoption-ready v0.7.0

[focaxisdev]

Why

The repository presents a one-command CLI onboarding path, but npm latest is still v0.1.0 and that published package has no deja-vu binary. New users following the current README therefore cannot complete the advertised quick start.

This PR prepares a real CLI-capable v0.7.0 release and removes first-run failure modes before launch.

What changed

• rebuilt the README around one-command setup, concrete before/after proof, precise compatibility claims, and a shareable product visual
• added deja-vu init --merge-agents so existing project rules are preserved and extended with an idempotent marked block
• made init report incomplete setup and made doctor reject an AGENTS.md that lacks Deja Vu recall rules
• added cross-platform starter-kit instructions, contributor guidance, launch copy, and a v0.7.0 release runbook
• added repository-wide local Markdown link validation and fixed broken memory-index template links
• upgraded package verification to build a tarball, install it in isolation, inspect bin metadata, and execute the packaged CLI
• bumped package metadata to v0.7.0 and recorded the remaining npm publish gate in repo-local memory

User impact

Fresh repos get the three required files with one command. Repos that already have AGENTS.md no longer receive a false-success setup: maintainers can safely append Deja Vu rules without losing existing instructions, and doctor verifies that the rules are actually present.

Validation

• npm ci — clean install; 0 known vulnerabilities
• npm test — source and compiled suites pass, 20/20 tests in each pass
• npm run check:links — 58 Markdown files checked
• npm run lint:memory — 0 errors, 0 warnings
• npm run report:feedback — successful
• root-memory lint — 0 errors, 0 warnings
• package verification — tarball installs and packaged deja-vu --help runs successfully
• git diff --check — clean

Release gate

This PR does not publish npm, create a tag, merge itself, or post launch copy. After review and merge, publish v0.7.0, verify npm view @focaxisdev/deja-vu version bin --json, smoke-test a fresh npx @focaxisdev/deja-vu init --dry-run, then create the matching GitHub release and begin the prepared launch sequence.