Embed webapp into the binary with fs-embed, drop --static-dir

ottyl was requiring webapp/dist to be shipped alongside the binary and
served via ServeDir/ServeFile pointed at a --static-dir CLI arg. Embed
the built webapp at compile time instead, so ottyl is a single
self-contained executable with no runtime static directory dependency.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFUNZwCvz3kcod3352ZR2o

tickets/028-fs-embed-static-bundling.md

@@ -1,37 +0,0 @@
-# 028 — Bundle the webapp with fs-embed, drop `--static-dir`
-
-## Summary
-
-`fs-embed` is already a `Cargo.toml` dependency but unused (`grep -rn
-"fs_embed" src/` turns up nothing) — `src/api.rs` still serves the webapp via
-`ServeDir`/`ServeFile` pointed at a `--static-dir` CLI arg
-(`src/main.rs:35`), which requires shipping `webapp/dist` alongside the
-binary. Embed the built webapp into the binary instead so `ottyl` is a single
-self-contained executable.
-
-## Scope
-
-- Use `fs-embed` to embed `webapp/dist` at build time.
-- Wire the embedded filesystem into `src/api.rs` in place of the
-  `ServeDir::new(static_dir).fallback(ServeFile::new(index_html))` setup
-  (`src/api.rs:100-101`), preserving the SPA fallback-to-`index.html`
-  behavior.
-- Remove the `--static-dir` clap arg (`src/main.rs:30-35`) and its plumbing
-  through `api::router` (`src/api.rs:91`, `src/main.rs:108`).
-- Update the test helper that builds a router against a temp static dir
-  (`src/api.rs:729-744`) to match the new embedding approach.
-- `webapp/dist` must exist at `cargo build` time (i.e. the webapp build step
-  stays a prerequisite) — document that in the README's build instructions if
-  not already covered.
-
-## Acceptance criteria
-
-- `cargo build` (with `webapp/dist` present) produces a binary that serves
-  the webapp with no `--static-dir` flag and no `webapp/dist` directory
-  needed at runtime.
-- `--static-dir` no longer appears in `--help` output or `Args`.
-- Existing API tests pass against the embedded-filesystem router.
-
-## Depends on
-
-None.