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/ai/blocklist/usage/conversation_usage_view.rs

@@ -1,5 +1,5 @@
 use crate::ai::blocklist::usage::render_context_window_usage_icon;
-use crate::ai::blocklist::view_util::{format_cost_cents, format_credits, format_token_count};
+use crate::ai::blocklist::view_util::{format_cost_cents, format_token_count};
 use crate::appearance::Appearance;
 use crate::persistence::model::{
     token_usage_category_display_name, ModelTokenUsage, FULL_TERMINAL_USE_CATEGORY,
@@ -26,10 +26,6 @@ pub enum DisplayMode {
 }
 
 pub struct ConversationUsageInfo {
-    pub credits_spent: f32,
-    // Credits spent over the last block, where the block comprises
-    // all agent outputs since the most recent user input.
-    pub credits_spent_for_last_block: Option<f32>,
     pub tool_calls: i32,
     pub models: Vec<ModelTokenUsage>,
     pub context_window_usage: f32,
@@ -144,28 +140,10 @@ impl ConversationUsageView {
         ));
         values.push(render_section_header("".to_string(), appearance));
 
-        if self.display_mode == DisplayMode::Footer
-            && self.usage_info.credits_spent_for_last_block.is_some()
-        {
-            let last_block_credits = self.usage_info.credits_spent_for_last_block.unwrap();
-            labels.push(render_label_text(
-                "Credits spent (last response)",
-                appearance,
-            ));
+        if self.usage_info.estimated_cost_cents > 0.0 {
+            labels.push(render_label_text("Estimated cost", appearance));
             values.push(render_value_text(
-                format_credits(last_block_credits),
-                appearance,
-            ));
-
-            labels.push(render_label_text("Credits spent (total)", appearance));
-            values.push(render_value_text(
-                format_credits(self.usage_info.credits_spent),
-                appearance,
-            ));
-        } else {
-            labels.push(render_label_text("Credits spent", appearance));
-            values.push(render_value_text(
-                format_credits(self.usage_info.credits_spent),
+                format_cost_cents(self.usage_info.estimated_cost_cents),
                 appearance,
             ));
         }
@@ -307,14 +285,6 @@ impl ConversationUsageView {
                     appearance,
                 ));
             }
-
-            if self.usage_info.estimated_cost_cents > 0.0 {
-                labels.push(render_label_text("Estimated cost", appearance));
-                values.push(render_value_text(
-                    format_cost_cents(self.usage_info.estimated_cost_cents),
-                    appearance,
-                ));
-            }
         }
 
         labels.push(render_label_text("Context window used", appearance));