feat: context pressure denominator, ambient sense formatting, resume timestamp, user nickname system, subagent background fork, settings LLM config, turn lifecycle, ledger lifecycle, subconscious evolution

- Context pressure footer now shows 'ctx 19% of 262k' (B-008)
- Ambient sense formatting as separate timestamp marker (B-010, T-034)
- Resume timestamp indicator with duration (T-032)
- User nickname system sourced from identity frontmatter (T-033)
- Subagent background fork task (B-009, T-031)
- Settings LLM config task (T-030)
- Turn lifecycle and sensorium completion task
- Ledger entry lifecycle task
- Subconscious evolution documentation
- Multimodal input metadata task
- Image support module (src/core/image.rs)
- Various refactors: config, seeds, session, consciousness engine, server modules, bridge, API handlers, TUI cockpit/commands/render, health panel, presence, setup wizard
- website/docs submodule update

src/api/models.rs

@@ -46,8 +46,14 @@ pub struct LlmConfig {
     /// if it arrives too quickly. Default 500ms.
     #[serde(default = "default_inter_round_delay")]
     pub inter_round_delay_ms: u64,
+    /// Whether this model supports image inputs (vision).
+    /// When false, images are stripped to text markers before sending.
+    #[serde(default = "default_supports_images")]
+    pub supports_images: bool,
 }
 
+fn default_supports_images() -> bool { true }
+
 fn default_context_window() -> u32 {
     128000
 }