docs(brand): rename to codewhale across READMEs and docs

Sweep brand mentions of `DeepSeek TUI` / `deepseek-tui` / bare
`deepseek` (the dispatcher binary) across all user-facing docs to
the new `codewhale` brand. The DeepSeek **provider** integration is
left untouched throughout: env vars (`DEEPSEEK_*`), model IDs
(`deepseek-v4-pro`, `deepseek-v4-flash`, `deepseek-chat`,
`deepseek-reasoner`), the `api.deepseek.com` host, the
`~/.deepseek/` config dir, and the `--provider deepseek` argument
value all keep the legacy spelling.

Anti-scope items deliberately left as the legacy `deepseek-tui`:

- Homebrew tap and formula (`Hmbown/homebrew-deepseek-tui`,
  `brew install deepseek-tui`, `scoop install deepseek-tui`). The
  tap rename ships separately.
- Docker image (`ghcr.io/hmbown/deepseek-tui`). Image-tag rename
  ships separately.
- CNB mirror namespace (`cnb.cool/deepseek-tui.com/DeepSeek-TUI`).
  Third-party hosted path.
- Security contact email (`security@deepseek-tui.com`).
- GitHub repo URL (`Hmbown/DeepSeek-TUI`).

New artifact:

- `docs/REBRAND.md` documents what changed, what didn't, the
  deprecation window, and migration commands for npm / Cargo /
  Homebrew / manual installs.

CHANGELOG entries:

- Root `CHANGELOG.md` and `crates/tui/CHANGELOG.md` both gain a
  new `[Unreleased]` section describing the rename and the one-
  release deprecation window. Historical entries are untouched.

Issue templates:

- `.github/ISSUE_TEMPLATE/bug_report.md` and `feature_request.md`
  refer to "codewhale" / `codewhale --version` instead of the old
  brand name in their environment fields.

The rebrand sweep was driven by a perl script with bulk patterns
(`deepseek-tui` -> `codewhale-tui`, `DeepSeek TUI` -> `codewhale`,
bare `deepseek` -> `codewhale` with provider/model/host/env-var/
config-path negative lookbehind/lookahead) followed by targeted
reverts for the anti-scope items above. Output was visually
reviewed file-by-file before committing.

Verified:

- `cargo check --workspace --all-targets --locked` — pass.
- `cargo test --workspace --all-features --locked` — pass (no
  test source touched here; suite stayed green to confirm no
  doc-from-string assertions broke).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/DOCKER.md

@@ -12,11 +12,11 @@ docker pull ghcr.io/hmbown/deepseek-tui:latest
 Run the published image with a Docker-managed data volume:
 
 ```bash
-docker volume create deepseek-tui-home
+docker volume create codewhale-tui-home
 
 docker run --rm -it \
   -e DEEPSEEK_API_KEY="$DEEPSEEK_API_KEY" \
-  -v deepseek-tui-home:/home/deepseek/.deepseek \
+  -v codewhale-tui-home:/home/deepseek/.deepseek \
   -v "$PWD:/workspace" \
   -w /workspace \
   ghcr.io/hmbown/deepseek-tui:latest
@@ -27,7 +27,7 @@ Use a pinned release tag for reproducible installs:
 ```bash
 docker run --rm -it \
   -e DEEPSEEK_API_KEY="$DEEPSEEK_API_KEY" \
-  -v deepseek-tui-home:/home/deepseek/.deepseek \
+  -v codewhale-tui-home:/home/deepseek/.deepseek \
   -v "$PWD:/workspace" \
   -w /workspace \
   ghcr.io/hmbown/deepseek-tui:vX.Y.Z
@@ -41,7 +41,7 @@ Replace `vX.Y.Z` with a tag from
 Build the image locally from a checkout:
 
 ```bash
-docker build -t deepseek-tui .
+docker build -t codewhale-tui .
 ```
 
 Then run it with the same Docker-managed data volume:
@@ -49,10 +49,10 @@ Then run it with the same Docker-managed data volume:
 ```bash
 docker run --rm -it \
   -e DEEPSEEK_API_KEY="$DEEPSEEK_API_KEY" \
-  -v deepseek-tui-home:/home/deepseek/.deepseek \
+  -v codewhale-tui-home:/home/deepseek/.deepseek \
   -v "$PWD:/workspace" \
   -w /workspace \
-  deepseek-tui
+  codewhale-tui
 ```
 
 Docker Hub publishing is not configured; GHCR is the supported prebuilt image
@@ -74,13 +74,13 @@ is the safest default because Docker creates it with ownership the container can
 write:
 
 ```bash
--v deepseek-tui-home:/home/deepseek/.deepseek
+-v codewhale-tui-home:/home/deepseek/.deepseek
 ```
 
 Without this mount the container starts fresh each time.
 
 If you bind-mount an existing host directory instead, the image runs as the
-non-root `deepseek` user with UID/GID `1000:1000`. The mounted directory must be
+non-root `codewhale` user with UID/GID `1000:1000`. The mounted directory must be
 writable by that user, or startup can fail while creating runtime directories
 under `.deepseek/tasks`. On Linux hosts, either use the named volume above or
 prepare the bind mount explicitly:
@@ -101,8 +101,8 @@ volume instead.
 
 ## Non-interactive / pipeline usage
 
-When stdin is not a TTY, `deepseek` drops to the dispatcher's one-shot mode
-(`deepseek -c "…"`). Pipe a prompt on stdin:
+When stdin is not a TTY, `codewhale` drops to the dispatcher's one-shot mode
+(`codewhale -c "…"`). Pipe a prompt on stdin:
 
 ```bash
 echo "Explain the Cargo.toml in structured English." | \
@@ -113,18 +113,18 @@ echo "Explain the Cargo.toml in structured English." | \
 
 ```bash
 # Single platform (your host architecture)
-docker build -t deepseek-tui .
+docker build -t codewhale-tui .
 
 # Multi-platform (requires a builder with emulation)
 docker buildx create --use
-docker buildx build --platform linux/amd64,linux/arm64 -t deepseek-tui .
+docker buildx build --platform linux/amd64,linux/arm64 -t codewhale-tui .
 ```
 
 ## Devcontainer
 
 The repository includes a [`.devcontainer/devcontainer.json`](../.devcontainer/devcontainer.json)
 configuration for VS Code / GitHub Codespaces. It pre-installs the Rust toolchain,
-rust-analyzer, and the `deepseek` binary. Open the repo in a devcontainer to get a
+rust-analyzer, and the `codewhale` binary. Open the repo in a devcontainer to get a
 ready-to-use development environment.
 
 ## Release status