Merge pull request #41 from coder/fix/node20-runtime

fix: target node20 so GHES 3.16 runners can load the action

fix: anchor github-url host to GITHUB_SERVER_URL for GHES support

Generate Zod schemas from codersdk via guts

Hand-maintained Zod schemas drifted from the Go SDK
and caused CODAGT-507. This replaces them with codegen.

scripts/typegen/ parses codersdk with guts, walks the
intermediate AST, and emits Zod v4 schemas to
src/codersdk.gen.ts. A daily CI cron checks for drift
against coder/coder tip.

ChatMessagePart is mapped to z.unknown() because guts
flattens the discriminated union into a single object.
CreateChatMessageResponse is hand-written since the
action only reads the queued field.

Modernize action runtime to Node 24

Node 20 is EOL. This moves the action to Node 24 and
updates every dependency to its current major version:

  @actions/core 1 -> 3, @actions/github 6 -> 9,
  zod 3 -> 4, TypeScript 5 -> 6, Biome 2.2 -> 2.4,
  Bun CI pin 1.3.13 -> 1.3.14.

Zod 4 tightened UUID validation to RFC 4122, which
broke test fixtures using zero-version UUIDs. TypeScript
6 stopped auto-loading ambient types, requiring an
explicit types array in tsconfig. Both fixed inline.

Removed unused @octokit/rest. Migrated deprecated
z.string().uuid()/url()/email() to top-level z.uuid()
etc. Removed dead esModuleInterop (always-on in TS 6).
Bumped target/lib to ES2024 to match Node 24.

dist/index.js is now marked linguist-generated in
.gitattributes so PR diffs and whitespace checks skip
the committed bundle.

v0.1.0: first usable release

Action creates Coder Agents chats from GitHub Actions workflows. Chat
owner is the coder-token holder; trigger policy is the workflow author's
responsibility via if: conditions.

See README for the input surface, security model, and example workflows.

docs(action.yaml): backtick github.actor and use canonical context te…

…rminology (#34)

On `action.yaml:62`, wrap `github.actor` in backticks for consistency with the surrounding identifiers (`gh-target`, `GITHUB_WORKFLOW`, `coder-token`) and replace "workflow expression" with the canonical GitHub Actions term "context value", per the [R2 review on #33](#33 (review)).

🤖 Authored by Coder Agents.