feat: Firefox selection translation extension with local Ollama (initial version)

Implement the complete initial version of a Firefox WebExtension (Manifest V3)
that translates selected text on web pages using a local Ollama LLM and shows
the result in a small popover near the selection.

Specification alignment (Phase 0)
- Unified Specifications.md / Design.md / Security.md on the same approach:
  Ollama REST API + Fetch API + NDJSON streaming (no ollama-js SDK dependency)
- Fixed host_permissions to http://localhost/* and http://127.0.0.1/* because
  Firefox match patterns do not support port numbers (bug 1362809/1468162);
  the actual connection target is restricted to localhost/127.0.0.1 + any port
  by application-side validation (defense in depth, OLL-09)
- Clipboard: use navigator.clipboard.writeText() only inside the copy button
  click (user activation); no deprecated execCommand fallback

Implementation (zero dependencies, vanilla JS, no npm/Node required)
- manifest.json: MV3, background.scripts + type:module (event page, no
  service_worker), action popup, options_ui, content_scripts for http/https,
  permissions: storage + localhost host permissions only
- src/shared: constants (ports, limits, presets, error codes), message
  validation, settings schema (defaults / merge / sanitize / buildOptions /
  toApiThinking), system prompt builder (fixed prompt first + user prompt)
- src/background: message-router (runtime.Port streaming + runtime.onMessage
  for model list), translation-session (single active request, abort previous
  on new request, stale chunk suppression), ollama-client (fetch against
  /api/tags and /api/chat with buffering NDJSON line parser tolerant to chunk
  boundaries inside JSON objects, AbortController, host re-validation before
  every request, HTTP status to error-code mapping), settings-service
  (storage.local load/save with validation and fallback to defaults)
- src/content/content.js: single classic script (Firefox does not support ES
  modules in content scripts) with selection detection (selectionchange +
  mouseup + keyup, debounced), Shadow DOM action button, Shadow DOM popover
  with HIDDEN/LOADING/STREAMING/COMPLETED/ERROR state machine, port client
  with requestId-based stale chunk filtering, enabled-state sync via
  storage.onChanged; all dynamic text rendered via textContent only
- src/popup + src/options: full settings UI (enable toggle, Ollama host,
  model list from Ollama with saved-model warning, target language, thinking
  mode, temperature slider 0.0-2.0 step 0.1, context length presets
  4k/8k/16k/32k/128k/256k, seed random/fixed with integer value, user system
  prompt, advanced numeric options with steppers, stop sequences textarea)
- icons generated by tools/make-icons.ps1 (System.Drawing, no external tools)
- build.ps1 packages manifest.json + icons/ + src/ into dist zip, excluding
  tests/, doc/, ollama-js/ and tools/

Tests (71 passed, 0 failed)
- In-browser test runner (tests/test.html) with custom describe/it/assert
  framework; no npm, no Node.js
- Unit: constants sync between content mirror and shared module, Ollama host
  validation (localhost/127.0.0.1 + any port only; rejects external hosts,
  LAN IPs, https, credentials, paths), settings schema defaults and fallback,
  temperature 0.1-step validation, context length presets, seed modes,
  advanced option types, buildOptions omission of unset values and absence of
  tfs_z/mirostat fields, system prompt composition order, message validation
  with selection length boundary values
- Integration: NDJSON streaming across awkward byte boundaries, thinking
  chunk forwarding, malformed line tolerance, error payload mapping, think/
  options inclusion rules, model list, TranslationSession abort semantics,
  settings round-trip with storage.onChanged cache refresh, full port flow
  (started/chunk/completed), newer request aborts older with stale chunk
  discard, malformed message rejection, OLLAMA_UNAVAILABLE and
  INVALID_SETTINGS error paths, untrusted sender rejection

Security audit (Design.md section 24 checklist: all pass)
- No innerHTML/outerHTML/document.write/eval/new Function/localStorage
- No remote JS/CSS/fonts/CDN resources; no inline scripts in extension pages
- Ollama access limited to background; content scripts never fetch Ollama
- Background validates message type/length/requestId; single concurrent
  translation enforced
- Clipboard API only (no execCommand fallback)
- Minimal permissions: storage + localhost host permissions

Docs
- README.md with build/load/usage instructions, API list, permission rationale
- doc/Testing-Results.md with automated test results, security audit results,
  and a 14-item manual Firefox verification checklist (to be executed on a
  real Firefox + Ollama environment)

1 files changed, 104 insertions, 0 deletions

diff --git a/src/options/options.html b/src/options/options.html
new file mode 100644
index 0000000..b60e66b
--- /dev/null
+++ b/src/options/options.html
@@ -0,0 +1,104 @@
+<!DOCTYPE html>
+<html lang="ja">
+<head>
+  <meta charset="utf-8">
+  <title>Ollama Translations - 設定</title>
+  <link rel="stylesheet" href="options.css">
+</head>
+<body>
+  <main>
+    <h1>Ollama Translations 設定</h1>
+
+    <form id="options-form" novalidate>
+      <fieldset>
+        <legend>基本設定</legend>
+
+        <div class="field">
+          <label class="switch-label">
+            <input type="checkbox" id="enabled" role="switch">
+            翻訳機能を有効にする
+          </label>
+        </div>
+
+        <div class="field">
+          <label for="ollama-host">Ollama Host</label>
+          <input type="text" id="ollama-host" placeholder="http://localhost:11434" spellcheck="false">
+          <p class="hint">初期版では http://localhost:&lt;port&gt; / http://127.0.0.1:&lt;port&gt; のみ接続できます。</p>
+        </div>
+
+        <div class="field">
+          <label for="model">Model</label>
+          <div class="inline">
+            <select id="model"></select>
+            <button type="button" id="reload-models">再取得</button>
+          </div>
+          <p id="model-status" class="status" hidden></p>
+        </div>
+
+        <div class="field">
+          <label for="target-language">翻訳先言語</label>
+          <select id="target-language"></select>
+        </div>
+
+        <div class="field">
+          <label for="thinking">Thinking</label>
+          <select id="thinking">
+            <option value="off">off</option>
+            <option value="on">on</option>
+            <option value="low">low</option>
+            <option value="medium">medium</option>
+            <option value="high">high</option>
+          </select>
+        </div>
+
+        <div class="field">
+          <label for="temperature">Temperature: <output id="temperature-value">0.2</output></label>
+          <input type="range" id="temperature" min="0" max="2" step="0.1" value="0.2">
+        </div>
+
+        <div class="field">
+          <label for="context-length">Context Length: <output id="context-length-value">16k</output></label>
+          <input type="range" id="context-length" min="0" max="5" step="1">
+          <p class="hint">4k / 8k / 16k / 32k / 128k / 256k</p>
+        </div>
+
+        <div class="field">
+          <span class="label-text">Seed</span>
+          <div class="segmented" role="radiogroup" aria-label="Seed mode">
+            <label><input type="radio" name="seed-mode" value="random"> 可変</label>
+            <label><input type="radio" name="seed-mode" value="fixed"> 固定</label>
+          </div>
+          <div class="inline" id="seed-value-row" hidden>
+            <label for="seed-value">固定値</label>
+            <input type="number" id="seed-value" step="1" placeholder="42">
+          </div>
+        </div>
+
+        <div class="field">
+          <label for="user-system-prompt">ユーザー用システムプロンプト</label>
+          <textarea id="user-system-prompt" rows="3" placeholder="例: カジュアルな口調で訳してください"></textarea>
+          <p class="hint">アプリ固定プロンプトと結合して送信されます。</p>
+        </div>
+      </fieldset>
+
+      <fieldset>
+        <legend>詳細設定（未設定項目は送信されません）</legend>
+        <div id="advanced-fields"></div>
+
+        <div class="field">
+          <label for="stop">stop（1行に1シーケンス）</label>
+          <textarea id="stop" rows="3" placeholder="例: &lt;END&gt;"></textarea>
+        </div>
+      </fieldset>
+
+      <div class="actions">
+        <button type="submit" id="save">保存</button>
+        <span id="save-status" class="status" role="status"></span>
+      </div>
+    </form>
+
+    <p class="dev-link"><a href="../../tests/test.html" target="_blank" rel="noreferrer">開発者向け: テストを実行</a></p>
+  </main>
+  <script src="options.js"></script>
+</body>
+</html>
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