feat(aligned-onboarding): seed report dashboard setup

[ioanahayman]

Summary

• Registers Aligned Onboarding as the manual package-index package for the package-manager surface.
• Adds the package-manager manifest for Aligned Onboarding, including skill and Brain resources installed under /agent/.agents/skills/aligned-onboarding/ and /agent/brain/aligned-onboarding/.
• Adds Report Dashboard Setup as the customer-owned reporting companion to Account Context Brain. It captures standard views, saved-report trust, source-of-truth rules, metric labels/order, thresholds, date windows, taxonomy, creative evidence, visual/delivery standards, cadence, and the validation surface in /agent/brain/meta/report-dashboard-context.md.
• Aligns the Account Context Brain, Report Dashboard Setup, Creative Corpus, and Motion CLI guide around the intended precedence: account interpretation in account-context.md, report/app packaging in report-dashboard-context.md, and creative evidence in the corpus.
• Keeps package-facing language on default Brain retrieval and customer-visible reporting surfaces, while treating corpus-search as an optional technical supplement for deliberate filterable search.
• Extends package-index validation so indexed packages are checked against package-local manifests and duplicate resource ids are rejected.

Functionality Preservation

• Package-owned setup docs install under /agent/brain/aligned-onboarding/; generated customer-owned setup stays visible and editable under /agent/brain/meta/.
• Account Context Brain remains the sole source for how the account is interpreted; Report Dashboard Setup controls report/app/dashboard packaging; Creative Corpus supplies stable creative evidence.
• Starter views, date windows, media treatment, and validation surfaces stay confirmable rather than stored as customer truth until the team or a trusted saved report proves them.
• The package remains manual and uninstallable, with no auto fleet rollout.

Validation

• node --test scripts/validate-runneth-package-index.mjs
• node -e "const fs=require('fs'); for (const f of ['package-index.json','aligned-onboarding/package.json','aligned-onboarding/install-config.json','aligned-onboarding/use-case.json']) JSON.parse(fs.readFileSync(f,'utf8')); console.log('json ok')"
• git diff --check
• git diff --check HEAD^..HEAD