v1.3.0: Bedrock translator refactor, usage metrics, session restore fixes, and predefined rules

Major changes:

- **Bedrock translator architecture**: Extract orchestration logic from `impl.rs` into
  a dedicated `translator.rs` module. Rename `convert_request.rs` → `request_translator.rs`
  and `stream.rs` → `response_translator.rs` for clarity. Remove `tool_docs.rs` (inlined).
  Remove `fallback_to_warp` setting and server fallback path — Bedrock is now the sole backend.

- **Unknown tool handling**: The response translator now detects hallucinated/unknown tool
  calls from the model and synthesizes error tool_results so the conversation doesn't
  deadlock waiting for a result that will never come.

- **Usage display overhaul**: Replace credit-based usage display with detailed token metrics
  showing context window %, cache hit rate (read/write/miss), and estimated cost in dollars.
  Add `total_input_tokens`, `total_cache_read_tokens`, `total_cache_write_tokens`, and
  `cache_miss_tokens` accessors to `AIConversation`.

- **Predefined rules system**: Add `predefined_rules.rs` with 11 system-defined behavioral
  rules that are auto-seeded on first launch. Add "Add Predefined Rules" button to the
  Rules UI for re-adding them later. Track seeding state via `has_seeded_predefined_rules`
  setting.

- **Session restore improvements**: Rename database file from `warp.sqlite` to
  `galaxy.sqlite` with automatic migration from both same-directory and state_dir legacy
  paths. Improve CWD persistence by falling back to `session_startup_path` for agent-mode
  and fresh tabs. Add extensive session-save/restore logging.

- **Shell bootstrap rebrand**: Rename `WARP_INITIAL_WORKING_DIR` environment variable to
  `GALAXY_INITIAL_WORKING_DIR` across bash, zsh, and fish bootstrap scripts.

- **Model defaults**: Change default Bedrock model from Opus 4.7 to Opus 4.6.
  Add `context_window_for_model()` helper with model-aware context sizes.
  Remove `is_bedrock_model()` (no longer needed without server fallback).

- **User query persistence**: The response translator now emits a `UserQuery` proto message
  at stream start so the user's prompt persists across sessions for conversation titles.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src/settings/ai.rs

@@ -1110,16 +1110,6 @@ define_settings_group!(AISettings, settings: [
         toml_path: "ai.bedrock.cross_region_inference",
         description: "Whether to automatically add cross-region inference prefixes to model IDs.",
     }
-    // Whether to fall back to routing through the Warp server when Bedrock credentials fail.
-    bedrock_fallback_to_warp: BedrockFallbackToWarp {
-        type: bool,
-        default: false,
-        supported_platforms: SupportedPlatforms::DESKTOP,
-        sync_to_cloud: SyncToCloud::Globally(RespectUserSyncSetting::Yes),
-        private: false,
-        toml_path: "ai.bedrock.fallback_to_warp",
-        description: "Whether to fall back to the Galaxy server when Bedrock credentials are invalid.",
-    }
     // Custom Bedrock model configurations.
     bedrock_models: BedrockModels {
         type: Vec<BedrockModelConfig>,
@@ -1528,6 +1518,17 @@ define_settings_group!(AISettings, settings: [
         toml_path: "agents.warp_agent.other.agent_attribution_enabled",
         description: "Whether the Galaxy Agent adds an attribution co-author line to commit messages and pull requests it creates.",
     }
+
+    // Tracks whether predefined system rules have been seeded on first launch.
+    // Once set to true, predefined rules will not be auto-created again even if the user
+    // deletes all their rules.
+    has_seeded_predefined_rules: HasSeededPredefinedRules {
+        type: bool,
+        default: false,
+        supported_platforms: SupportedPlatforms::ALL,
+        sync_to_cloud: SyncToCloud::Globally(RespectUserSyncSetting::No),
+        private: true,
+    }
 ]);
 
 impl AISettings {
@@ -1992,6 +1993,14 @@ impl AISettings {
             .plugin_update_chip_dismissed_for_version_map
             .set_value(map, ctx));
     }
+
+    pub fn has_seeded_predefined_rules(&self) -> bool {
+        *self.has_seeded_predefined_rules
+    }
+
+    pub fn mark_predefined_rules_seeded(&mut self, ctx: &mut ModelContext<Self>) {
+        report_if_error!(self.has_seeded_predefined_rules.set_value(true, ctx));
+    }
 }
 
 /// Singleton model that caches compiled regexes for the `cli_agent_footer_enabled_commands`