refactor: remove legacy Twist/migration framing

[amix]

Context

This SDK was bootstrapped from twist-sdk-typescript; the bootstrap commit
carried over a lot of legacy framing ("as of the UUIDv7 migration", "what's
gone vs. legacy Twist", Comms_API_changes.md references, Twist branding in
the Docusaurus site). Treating it as a clean hard fork makes the docs read
like a first-class SDK and stops the migration narrative from rotting in
place.

What was changed

• README: dropped the "IDs are base58-encoded UUIDv7" and "What's gone vs. legacy Twist" sections; rewrote the creation guidance as plain SDK doc.
• Website (docusaurus.config.ts, docs/index.md, docs/authorization.md): renamed Twist* → Comms* everywhere, switched logo/social-card to the already-present Todoist assets, removed twist-logo.png.
• Source comments: stripped UUIDv7-migration framing, Comms_API_changes.md references, and "as of the Todoist-id migration" prose from every client docstring and from src/types/{entities,requests,enums}.ts, src/utils/{uuidv7,url-helpers}.ts, and test-default comments.
• Also includes incidental refactor: StatusOkSchema / StatusOk hoisted into src/types/entities.ts, per-client XListSchema = z.array(XSchema) helpers, and add-comment-helper.ts combines both groups / directGroupMentions marker offenses into a single error.

Out of scope

• Did not rename internal symbol names in src/utils/uuidv7.ts (e.g. encodeUuidToBase58, UuidV7Error) — these describe what the code does, not migration history, and renaming the public exports would break the API.
• inbox-client.ts still uses inline z.array(InboxThreadSchema) rather than a hoisted InboxThreadListSchema; mirroring the rest of the codebase can be a follow-up.

[doistbot]

This PR does a great job cleaning up the legacy Twist and migration framing to help the SDK stand on its own as a first-class library. The extensive documentation updates and incidental refactoring significantly improve the overall clarity and maintainability of the codebase. To wrap things up, there are a few adjustments needed, including exporting the newly introduced list schemas, tightening up the StatusOk schema and creation ID documentation to accurately reflect their strict constraints, and adding targeted tests to cover the combined error branch and parameter serialization.

_{Share Feedback • Review Logs}

[amix]

All 12 review comments are addressed in 480fd0f. Summary:

Comments	Fix
1–7 (*ListSchema exports)	All six list schemas + the workspaces.getPublicChannels one are now export const ....
8 (README claims wider contract than resolveCreateId honors)	README now explicitly says caller-supplied id must be a base58-encoded UUIDv7.
9 (StatusOkSchema looser than its doc)	Narrowed to z.object({ status: z.literal('ok') }).
10 (combined-error branch untested)	New src/clients/add-comment-helper.test.ts covers markers in groups only, in directGroupMentions only, in both at once, plus the notifyAudience translation. The test surfaced a real bug: a circular import (entities ↔ enums) was leaving the marker constants undefined at init time, so the rejection guard was dead. Fixed by moving EVERYONE / EVERYONE_IN_THREAD / GROUP_ID_MARKERS / GroupId into ./enums.
11 (comments-client rename untested)	New src/clients/comments-client.test.ts pins thread_id, newer_than_ts, older_than_ts, and comment_id on the wire (GET + POST + batch descriptor).
12 (conversation-messages-client rename untested)	New src/clients/conversation-messages-client.test.ts pins conversation_id, newer_than_ts, older_than_ts, direct_mentions, and direct_group_mentions on the wire (GET + POST + batch descriptor).

104 → 115 tests, type-check + lint + format all green.