i18n: Japanese for the whole interface

ja.tsv now has the same 3,466 entries as es.tsv (menus, panels, dialogs,
the Settings pages, the Effects registry, Keyboard Shortcuts, tooltips and
status messages) instead of 89 menu-only entries.

The 46 old rows that came from PhotoCraft/PDFCraft and match no FilmCraft
string are dropped. Five rows that were wrong for a video editor are
fixed: Horizontal/Vertical are 水平/垂直 (every use is geometry, not
writing direction), Orientation is 向き, Type is 種類 and Effect is
エフェクト. The other 38 rows that were already in use are unchanged.

ROADMAP.md and crates/ui-egui/README.md now list Japanese next to Spanish
as covering the whole interface.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

ROADMAP.md

@@ -211,4 +211,4 @@ Status: ✅ done · 🟡 in progress · ⬜ not started. Estimates are remaining
 
 ### Interface localization
 
-Edit > Language switches English/Japanese/Spanish/Portuguese (Brazilian) and persists across restarts through `general.interfaceLanguage` (also available in Settings > General). Until a language is chosen, System Language (the default) follows the operating system's or browser's preferred languages and falls back to English. Commands `app.language.english`, `app.language.japanese`, `app.language.spanish` and `app.language.portuguese` are reachable through the control channel. Translations live in one catalog per language (`crates/ui-egui/src/i18n/<code>.tsv`); UI code wraps its strings in `tl!("…")` / `tlf!("…{name}", name)`, and names that come from registries (effects and their parameters, settings, commands, panels, workspaces, presets) are translated where they are drawn. **Spanish covers the whole interface**: menus, panels, dialogs, the Settings pages, the Effects/Effect Controls registry, the Keyboard Shortcuts dialog and status messages; tests fail when a `tl!` literal, a menu label or a registry name has no Spanish entry. Searches match the displayed labels as well as English sources. Japanese and Brazilian Portuguese cover the core menus; untranslated labels use English. Engine error messages, the control channel, the CLI and MCP stay in English. Japanese text uses the Japanese fonts from [craft-fonts](https://github.com/storytold/craft-fonts) when FilmCraft is built with them (`CRAFT_FONTS_DIR`; all official releases, including the web build), otherwise a Japanese font already installed on the system; with neither, switching to Japanese is refused with a message. Existing vertical text support is preserved.
+Edit > Language switches English/Japanese/Spanish/Portuguese (Brazilian) and persists across restarts through `general.interfaceLanguage` (also available in Settings > General). Until a language is chosen, System Language (the default) follows the operating system's or browser's preferred languages and falls back to English. Commands `app.language.english`, `app.language.japanese`, `app.language.spanish` and `app.language.portuguese` are reachable through the control channel. Translations live in one catalog per language (`crates/ui-egui/src/i18n/<code>.tsv`); UI code wraps its strings in `tl!("…")` / `tlf!("…{name}", name)`, and names that come from registries (effects and their parameters, settings, commands, panels, workspaces, presets) are translated where they are drawn. **Spanish and Japanese cover the whole interface**: menus, panels, dialogs, the Settings pages, the Effects/Effect Controls registry, the Keyboard Shortcuts dialog and status messages; tests fail when a `tl!` literal, a menu label or a registry name has no Spanish entry (`ja.tsv` has the same entries, but the tests do not require them yet). Searches match the displayed labels as well as English sources. Brazilian Portuguese covers the core menus; untranslated labels use English. Engine error messages, the control channel, the CLI and MCP stay in English. Japanese text uses the Japanese fonts from [craft-fonts](https://github.com/storytold/craft-fonts) when FilmCraft is built with them (`CRAFT_FONTS_DIR`; all official releases, including the web build), otherwise a Japanese font already installed on the system; with neither, switching to Japanese is refused with a message. Existing vertical text support is preserved.

crates/ui-egui/README.md

@@ -19,10 +19,10 @@ fills translated templates, and `i18n::t` translates names from registries. Plac
 (including user filenames containing braces) are inserted literally. Catalog translations are
 original work using ordinary language, without proprietary localisation resources.
 
-Spanish covers menus, panels, dialogs, settings and registry labels. Searches accept both the
+Spanish and Japanese cover menus, panels, dialogs, settings and registry labels. Searches accept both the
 translated label and its English source, including Unicode capitals. Project content, command ids
 and preference values retain their original values. Engine errors, CLI and MCP messages remain
-English; Japanese currently covers core menus and falls back to English elsewhere.
+English; Brazilian Portuguese currently covers core menus and falls back to English elsewhere.
 
 Verification: `cargo test -p filmcraft-ui-egui` checks catalog syntax, duplicate keys, placeholders,
 literal/menu/registry coverage and UI behaviour; `cargo xtask ci` runs the workspace gates. Visual