fix: consistent zero-padding and file naming across agents

- plan-phase.md: zero-pad phase number in mkdir
- roadmapper: explicit zero-padding instruction with printf
- discuss-phase workflow: use PADDED_PHASE in file paths
- planner: fix {plan}-PLAN.md -> {phase}-{plan}-PLAN.md
- researcher: fix double-path bug in git add command
- researcher: add CONTEXT.md loading from discuss-phase

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

get-shit-done/workflows/discuss-phase.md

@@ -229,7 +229,9 @@ Track deferred ideas internally.
 <step name="write_context">
 Create CONTEXT.md capturing decisions made.
 
-**File location:** `.planning/phases/${PHASE}-${SLUG}/${PHASE}-CONTEXT.md`
+**File location:** `.planning/phases/${PADDED_PHASE}-${SLUG}/${PADDED_PHASE}-CONTEXT.md`
+
+Zero-pad the phase number: `PADDED_PHASE=$(printf "%02d" ${PHASE})`
 
 Create phase directory if it doesn't exist. Use roadmap phase name for slug (lowercase, hyphens).
 
@@ -294,7 +296,7 @@ Write file.
 Present summary and next steps:
 
 ```
-Created: .planning/phases/${PHASE}-${SLUG}/${PHASE}-CONTEXT.md
+Created: .planning/phases/${PADDED_PHASE}-${SLUG}/${PADDED_PHASE}-CONTEXT.md
 
 ## Decisions Captured