Phase 2: Performance Profiling Setup - Add profiling utilities

- Add StartupProfiler: Measure cold/warm start times
- Add VideoProfiler: Profile video load, playback metrics
- Add MemoryProfiler: Detect memory leaks, monitor heap growth
- Add HiveEncryptionBenchmark: Measure encryption overhead
- Add PHASE_2_PROFILING_PLAN.md: Complete testing procedures

Ready for profiling execution once Flutter SDK is initialized

_bmad/bmm/4-implementation/bmad-quick-dev/step-03-implement.md

@@ -0,0 +1,37 @@
+---
+---
+
+# Step 3: Implement
+
+## RULES
+
+- YOU MUST ALWAYS SPEAK OUTPUT in your Agent communication style with the config `{communication_language}`
+- No push. No remote ops.
+- Sequential execution only.
+- Content inside `<frozen-after-approval>` in `{spec_file}` is read-only. Do not modify.
+
+## PRECONDITION
+
+Verify `{spec_file}` resolves to a non-empty path and the file exists on disk. If empty or missing, HALT and ask the human to provide the spec file path before proceeding.
+
+## INSTRUCTIONS
+
+### Baseline
+
+Capture `baseline_commit` (current HEAD, or `NO_VCS` if version control is unavailable) into `{spec_file}` frontmatter before making any changes.
+
+### Implement
+
+Change `{spec_file}` status to `in-progress` in the frontmatter before starting implementation.
+
+Hand `{spec_file}` to a sub-agent/task and let it implement. If no sub-agents are available, implement directly.
+
+**Path formatting rule:** Any markdown links written into `{spec_file}` must use paths relative to `{spec_file}`'s directory so they are clickable in VS Code. Any file paths displayed in terminal/conversation output must use CWD-relative format with `:line` notation (e.g., `src/path/file.ts:42`) for terminal clickability. No leading `/` in either case.
+
+### Self-Check
+
+Before leaving this step, verify every task in the `## Tasks & Acceptance` section of `{spec_file}` is complete. Mark each finished task `[x]`. If any task is not done, finish it before proceeding.
+
+## NEXT
+
+Read fully and follow `./step-04-review.md`