docs: prepare 0.2.0 release narrative (#99)

Reframe the contract docs from the `0.1.x` beta line to the upcoming
`0.2.x` stable line ahead of cutting v0.2.0 as the first stable release.

- `RELEASE.md`: replace the inaccurate "original 0.1.0 release
  established the baseline" claim (no `v0.1.0` tag, GitHub release, or
  npm version ever existed) with an accurate statement that the `0.1.x`
  beta line established the baseline and `0.2.0` is the first stable
  cut on top of it.
- `ROADMAP.md`, `README.md`, `design/ARCHITECTURE.md`: substitute
  `0.1.x` → `0.2.x` in the "current release line" narrative sentences.
  Historical references (e.g. "pre-`0.1.0` release-readiness milestone"
  on `design/ARCHITECTURE.md:43`) are left alone.
- `CHANGELOG.md`: add a Notes section to the Unreleased block
  documenting that `protocolVersion` intentionally stays at `0.1.0` —
  the upcoming release is additive over the `0.1.x` envelope contract
  and does not change the public JSON shape; only the package version
  moves to `0.2.0`.

The `[Unreleased]` header itself is intentionally not renamed to
`[v0.2.0] - <date>` in this PR. That rename belongs in the
release-prep commit so the Release Changelog workflow's
"does this version header already exist?" check sees a coherent state
across the version-bump.

`dogfood/CATALOG.md:27` ("Current release-signoff bundle for the
`0.1.0` bar.") is also intentionally not touched here; it should be
updated in the follow-up PR that adds the fresh `v0.2.0`-era
release-readiness dogfood bundle.

Change-Id: Iacd16a123d491b6fa87748c6aa405afe9a8318a1

Signed-off-by: Thomas Kosiewski <tk@coder.com>

Author: ThomasK33

CHANGELOG.md

@@ -27,6 +27,10 @@
 - Default-location screenshot PNGs, snapshot JSON files, and `record export` artifacts are now rolled back when the subsequent artifact-manifest append fails, so a manifest-validation failure no longer leaves an orphaned, unmanifested file under the session's `artifacts/` directory. Explicit `--out` paths supplied by the caller are preserved on failure because they belong to the user, not the session manifest ([#95](https://github.com/coder/agent-tty/pull/95), fixes [#79](https://github.com/coder/agent-tty/issues/79)).
 - `EventLog.open` now closes the underlying file handle when validation (size-limit check or existing-content parsing) fails, preventing a file-descriptor leak on rejected session host startup ([#51](https://github.com/coder/agent-tty/pull/51)).
 
+### Notes
+
+- `protocolVersion` in the `version` envelope intentionally stays at `0.1.0`. This release is additive over the `0.1.x` envelope contract and does not change the public JSON shape; only the package version moves to `0.2.0`.
+
 ## [v0.1.1-beta.4](https://github.com/coder/agent-tty/releases/tag/v0.1.1-beta.4) - 2026-04-25
 
 ### Added

README.md

@@ -166,7 +166,7 @@ For TanStack Intent, Mux, and direct skill-copy instructions, see [`docs/AGENT-S
 
 ## Vision And Roadmap
 
-The current `0.1.x` line is centered on reliable, isolated, reviewable TUI automation through the CLI.
+The current `0.2.x` line is centered on reliable, isolated, reviewable TUI automation through the CLI.
 Future work includes native renderer adapters, broader platform parity, mouse input, richer semantic TUI automation, remote/networked control, and external control layers such as an MCP wrapper.
 
 - [`RELEASE.md`](./RELEASE.md) defines the supported release contract.

RELEASE.md

@@ -1,7 +1,7 @@
 # agent-tty release contract
 
-This document defines the supported product contract for the current `0.1.x` release line.
-The original `0.1.0` release established the baseline for isolated, reviewable terminal automation for real TUI workflows; later `0.1.x` releases may add compatible fixes and features without widening this core support contract.
+This document defines the supported product contract for the current `0.2.x` release line.
+The `0.1.x` beta line established the baseline for isolated, reviewable terminal automation for real TUI workflows, and `0.2.0` is the first stable cut on top of that baseline; later `0.2.x` releases may add compatible fixes and features without widening this core support contract.
 If a workflow depends on behavior outside this document, treat it as future-scope or best-effort rather than a guaranteed capability.
 
 For per-release changes, see [`CHANGELOG.md`](./CHANGELOG.md). For release mechanics, use [`docs/RELEASE-PROCESS.md`](./docs/RELEASE-PROCESS.md). For intentionally deferred work, see [`ROADMAP.md`](./ROADMAP.md). For reviewer-facing proof bundles, start with [`dogfood/CATALOG.md`](./dogfood/CATALOG.md).

ROADMAP.md

@@ -1,6 +1,6 @@
 # agent-tty roadmap
 
-`RELEASE.md` defines what the current `0.1.x` line supports. This roadmap tracks intentionally deferred work and post-release direction so the repository front door separates shipped scope from future scope.
+`RELEASE.md` defines what the current `0.2.x` line supports. This roadmap tracks intentionally deferred work and post-release direction so the repository front door separates shipped scope from future scope.
 For historical week-by-week planning and status context, see [`design/archive/`](./design/archive/). For the stable design overview, see [`design/ARCHITECTURE.md`](./design/ARCHITECTURE.md).
 
 ## Near-term refinements

design/ARCHITECTURE.md

@@ -21,7 +21,7 @@ This design intentionally describes a **general product**, not a Mux-specific im
 
 ## Current shipped status
 
-The current `0.1.x` line is centered on reliable, isolated, reviewable terminal and TUI automation. The shipped surface includes `run` for robust in-session command execution, renderer/browser-path handling that respects isolated-home workflows, and isolation-aware `doctor --json` diagnostics on top of lifecycle, snapshot, screenshot, and export work. Larger asks such as native renderers, mouse input, remote/network sessions, MCP wrapping, and broader semantic TUI automation remain intentionally deferred and tracked in [`../ROADMAP.md`](../ROADMAP.md).
+The current `0.2.x` line is centered on reliable, isolated, reviewable terminal and TUI automation. The shipped surface includes `run` for robust in-session command execution, renderer/browser-path handling that respects isolated-home workflows, and isolation-aware `doctor --json` diagnostics on top of lifecycle, snapshot, screenshot, and export work. Larger asks such as native renderers, mouse input, remote/network sessions, MCP wrapping, and broader semantic TUI automation remain intentionally deferred and tracked in [`../ROADMAP.md`](../ROADMAP.md).
 
 The repository now ships the first three milestones of this design plus Weeks 4–7 of CLI/artifact/lifecycle hardening, config/rendering/platform closeout, contract/introspection reconciliation, and Week 7 contract/doc ratification: