ghcp-mon v0.0.8

• New ghcp-mon export <session> subcommand — writes a session's spans as replay-compatible JSON lines to -o <path> or stdout; pipe straight into ghcp-mon replay. Includes span events, ordered by start time, metrics/logs excluded. Missing sessions fail fast without touching the output file.
• Context Growth Widget: cache-read tokens shown as a green segment at the base of every chat bar (root and sub-agent), with the tooltip disclosing cache vs. fresh input.
• Live span ingest now smoothed over a 2s window (newest-first, capped at 60 reveals/sec, parent-before-child preserved) so batch arrivals visually convey ingestion rate instead of popping in all at once.
• Diff-stat badges on span rows for edit / create / apply_patch — red -N removed, green +M added.
• Inline description label on tool span rows — surfaces the model-supplied intent (e.g. for bash / task calls) without chip chrome.
• Tool Detail: hero panel surfaces the key function argument (command → query → description, first match wins) in a high-contrast block above args/result.
• Tool Detail: metadata panel is now a collapsible <details>, closed by default, keeping args/result and the hero panel above the fold.
• Vendor-aware session rows — local_name, the auto badge, and the branch chip now render only when service_name === "github-copilot"; sessions from other OTLP producers fall back to vendor-agnostic fields.
• Normalization picks up Copilot turn identifiers (github.copilot.interaction_id / turn_id on chat_turns) and classifies external_tool* spans as a distinct ExternalTool kind, routing them to the external_tool_calls table.