[codex] Split PersonalOS into independent plugins

[artpi]

Summary

This PR splits the PersonalOS monolith into a lean family of independently installable, WordPress.org-ready Personal plugins built around the shared Knowledge/Guidelines runtime.

The split keeps shared runtime behavior in bundled helper classes, not a required base plugin, so every generated ZIP can install on its own and interoperate through WordPress-native surfaces: Knowledge posts, Knowledge type terms, REST, cron, post meta, user meta, and the Abilities API.

Sub-plugin features

Personal Notes (personal-notes)

• Adds a standalone Notes admin UI over resolved Knowledge rows.
• Creates and edits private user-authored note artifacts tagged with artifact, note, and source terms such as manual.
• Owns PARA/Knowledge type management for note-like content, including child term creation under supported containers.
• Registers the package-owned pos/note block and package-local editor assets.
• Displays note-like Knowledge from manual notes and synced sources without requiring Readwise or Evernote plugins.

Personal Readwise Sync (personal-readwise-sync)

• Stores per-user Readwise settings: token, autotag, cursor, and last sync state.
• Syncs Readwise export data into private Knowledge records tagged with artifact, note, readwise, synced, and reference.
• Preserves Readwise metadata such as readwise_id, category, author, source URL, and source hashes.
• Registers package-owned pos/readwise and pos/book-summary blocks.
• Reworks the book summary block to use a package REST endpoint backed by WordPress AI Client/Connectors instead of the old /pos/v1/openai/* route.
• Documents Readwise API and optional AI summary privacy behavior in the package readme.

Personal Evernote Sync (personal-evernote-sync)

• Stores per-user Evernote settings: token, active flag, synced notebook GUIDs, USN, last sync/update count, and cached notebook/tag metadata.
• Adds package-owned one-way Evernote import transport that loads the bundled Evernote SDK runtime when available.
• Imports matching sync-chunk notes into private Knowledge rows tagged with artifact, note, evernote, synced, and reference.
• Preserves evernote_guid, evernote_content_hash, source URLs, source hashes, and per-user ownership.
• Bundles only the standalone runtime vendor files needed by the ZIP: Evernote Cloud SDK plus PSR Log license/runtime files.
• Keeps normalized transport seams for tests and future SDK refinement without depending on the old Notes module.

Personal TODO (personal-todo)

• Adds a standalone TODO admin app and fallback UI over Knowledge task artifacts.
• Stores each actionable task as its own Knowledge post tagged with artifact and todo, without using plan or ordinary personalos terms.
• Preserves task operational meta such as reminders_id, pos_blocked_by, pos_blocked_pending_term, pos_recurring_days, and URL.
• Keeps task history as todo_note comments attached to the task Knowledge post.
• Supports create, list, update, complete, search, term filtering, recurrence, scheduled tasks, and unblock side effects.
• Folds in the per-user ICS feed and resolves feed tokens back to the owning user before querying private tasks.
• Registers TODO Abilities API tools for list/create/update/complete when the Abilities API is available.

Personal AI Chat (personal-ai-chat)

• Adds a standalone AI Chat admin app over Knowledge conversation rows.
• Stores chat transcripts as private Knowledge conversations tagged with artifact, conversation, ai-chat, and personalos.
• Registers AI message and AI tool blocks as package-owned blocks.
• Provides REST endpoints for conversations, messages, generation, setup status, and ability discovery.
• Uses WordPress AI Client through wp_ai_client_prompt()->generate_text() when available, with Connectors/provider setup kept outside the package.
• Discovers tools through wp_get_abilities() instead of depending on TODO or Notes PHP classes.
• Activates without sibling Personal packages and shows setup status when AI Client or Abilities are missing.

Shared split foundation

• Adds bundled helper classes for Knowledge runtime resolution, Knowledge type vocabulary, package settings, assets, notices, health checks, plugin base behavior, and sync base behavior.
• Resolves future Knowledge identifiers first and falls back to current Guidelines identifiers.
• Normalizes the PARA-inspired Knowledge type vocabulary with container-only parent terms and assignable child terms.
• Keeps shared helpers source-controlled once under shared/php and copies them into each ZIP under includes/shared during packaging.
• Uses package-local text domains for standalone WordPress.org packages.

Build, packaging, and local dev

• Adds package-aware webpack entries and syncs built assets into packages/<slug>/build after npm run build.
• Adds tools/package-plugin.mjs to build one ZIP per package.
• Adds tools/verify-split-packages.mjs as a store-readiness gate for headers, readmes, privacy disclosures, ZIP shape, bundled helpers, block assets, vendor runtime files, and monolith/sibling coupling.
• Updates GitHub Actions to build and upload a ZIP matrix for all five packages.
• Updates release workflow to upload all five package ZIPs.
• Replaces default .wp-env.json with the split package suite and adds one-package wp-env configs plus a legacy Abilities config.

Validation

Passed locally:

• npm run build
• npm run package:plugins
• npm run verify:split-packages
• focused PHPCS/PHP syntax checks for package PHP and split tests
• focused JS lint checks for changed package/tooling files
• git diff --check

Known local environment blocker:

• npm run test:unit:backend could not run because wp-env reports service "tests-cli" is not running container #1. Per repo instructions, I did not try to repair the wp-env environment.

Build warnings observed but not introduced by the split package path:

• stale Browserslist data
• existing root monolith warning for src/notebooks/notebooks.js importing missing flag from @wordpress/icons
• existing root index.js bundle size warnings