fix(#464): redefine_classes re-resolves statement anchors against the new source

[debugmcpdev]

Closes #464.

A hot-swap invalidates line numbers, but the replant was purely by line — a statement:-anchored breakpoint silently rebound to whatever now lives at the old line, reporting verified: true. Content identities must be honored whenever line numbers are invalidated, as restart_debugging already does.

Fix

• After a successful redefine (redefinedCount > 0), reresolveAnchors — the restart machinery, with all its awkward parts already solved (fresh file read, nearLine proximity, Substring expectedContent silently weakens the 'cannot land on the wrong line' guarantee; docs still promise it #379 multi-candidate flagging, [FEATURE] Agent-native breakpoint addressing: expectedContent assertion, statement anchors, function breakpoints #271 stale-keeps-line) — re-resolves every statement anchor against the source on disk, and the affected files are re-sent via the existing per-file setBreakpoints sync. Ordered after vm.redefineClasses by construction (it runs on the redefine response), so the JDI replant binds moved lines against the new line table — the "not a drop-in" part the issue called out.
• The response carries the same anchorResolution: { moved, stale } shape restart_debugging returns, plus a warning when anchors went stale or a re-send failed.
• Bridge drive-by fixed: handleClassPreparedForFunctionBreakpoints now returns its replant count and replantBreakpointsAfterRedefine adds it in, so replantedBreakpoints stops under-reporting (visible below: it reports 2 for 1 line + … well, 2 line bps here).

Verification — the issue's literal repro, live

Breakpoint at line 19 + statement-anchored breakpoint on System.out.println("val2 = " + val2); (line 23). Launch, pause at 19. Overwrite the source with the V2 file (statement shifts to 26), javac -g, redefine_classes:

→ { redefinedCount: 1, replantedBreakpoints: 2,
    anchorResolution: { moved: [{ from: 23, to: 26, statement: "System.out.println(\"val2 = \" + val2);" }], stale: [] } }
continue_execution
→ stops at RedefineTarget.main line 26      // previously: ran to completion
evaluate val2 → "99"                        // the hot-swapped value

• New unit tests: moved anchor (with post-redefine setBreakpoints ordering asserted), stale anchor + warning, nothing-redefined short-circuit.
• JdiDapServer.java compiles clean; full unit suites 3221 passed.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/session/session-manager-operations.ts	92.30%	1 Missing ⚠️

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