feat(trace): port redaction engine, skill events, and token profiler from entire-eco/cli

[Patel230]

Summary of Changes

This PR ports core capabilities, privacy filter engines, agent skill event parsers, token usage profilers, and foreground execution helpers from entire-eco/cli to graycode-eco/trace while maintaining local-first contracts and ecosystem boundaries.

Key Modules Ported

1. Redaction Engine & Privacy Filters (redact/)

   • OPF runtime, binary detection, and category filtering (redact/opf.go, redact/opf_test.go).
   • Supabase secret pattern detectors (sb_secret_, sbp_) (redact/providers.go).
   • Batched bytes redaction (redact/batch.go, redact/batch_test.go).
   • Extended redactor with privacy filter support (redact/redact.go).

2. Agent Skill Events & Launchers (cli/agent/)

   • Skill event type definitions and extractor interface (cli/agent/types/skill_events.go, cli/agent/skill_events.go).
   • Prompt slash command parser with filesystem path guards (cli/agent/skill_events_prompt.go).
   • Model listing capability (cli/agent/model_lister.go).
   • Foreground interactive process execution helper (cli/agent/foreground.go).

3. Token Usage Diagnostics (cli/)

   • trace session tokens and trace session tokens --agent-brief (cli/session_tokens.go).
   • trace tokens profile committed checkpoint aggregator (cli/tokens_profile.go).
   • Registered tokens command group in cli/root.go.
   • Added SkillEvents field to session state (cli/session/state.go).

Verification

• go fmt ./... passed (0 formatting diffs)
• go build ./... passed (exit code 0)
• go test -v ./redact/... ./cli/agent/... passed (100% test pass rate)