add donor analysis and initialization sessions

[NetVar1337]

summary

• report donor identity, capabilities, BAR layout, generated write masks, and validation issues
• reject malformed capability chains, invalid 64-bit BAR5 layouts, and out-of-bounds MSI-X placement
• capture checksummed initialization sessions with config, PCI resources, interrupt snapshots, and width-aware MMIO traces
• support guarded trace, driver unbind/bind, and interface down/up capture scenarios with restoration paths
• compare repeated sessions into phases, register evidence, polling loops, write effects, dependencies, config transitions, confidence, and MAC candidates

affected modules

• cmd/pcileechgen
• internal/donor/session
• internal/donor/mmio
• internal/pci
• internal/firmware/codegen

tests

• go test ./...
• go test -race ./...
• changed-package golangci-lint passes
• offline multi-session text and JSON smoke tests

make check still reports pre-existing lint findings in untouched internal/firmware/scrub, internal/firmware/output, and existing output tests; changed packages are clean.

[sercanarga]

this pr has been closed bec. #79 continued