docs: program plan — full E1→E10 decomposition

[ArthurBernard]

The complete map of the rewrite before execution: every epic (E1→E10) broken
into its leaves, each leaf with its branch, complexity, dependencies
and intent. Removes grey zones on direction & structure. Executable file-by-file
specs are written epic-by-epic just before each runs (E1's tree is PR #4).

New: doc/dev/08-program-plan.md (linked from 07-roadmap.md and doc/dev/README.md).

Highlights

• 34 leaves across 10 epics (E1 5 · E2 3 · E3 3 · E4 5 · E5 3 · E6 3 · E7 4 · E8 3 · E9 2 · E10 3).
• Dependency graph: E1→E2→E3→E4→{E5,E6}→E7→E8→{E9,E10}. Parallel: E2's leaves; E5∥E6; E9∥E10.
• MVP "first light" at end of E7 (CLI runs a strategy on Kraken in paper mode, with risk + reconciliation).
• Deferred decisions pinned to where they resolve: fynance-typing→E1-05, dccd-depth→E8-02, paper-vs-live default→E10-02, final name→E10-03.

Review alongside PR #4 (E1 tree). Once both look right: merge → /execute-leaf domain-core next.